S4D430
Building Views in Core Data
Services ABAP (CDS ABAP)
.
.
PARTICIPANT HANDBOOK
INSTRUCTOR-LED TRAINING
.
Course Version: 10
Course Duration: 3 Day(s)
e-book Duration: 24 Hours
Material Number: 50142171
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iii
Typographic Conventions
American English is the standard used in this handbook.
The following typographic conventions are also used.
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Contents
vii
Course Overview
1
Unit 1:
2
14
19
23
35
43
Lesson: Motivating CDS Views and Understanding the Background
Lesson: Working with ABAP Development Tools (ADT)
Exercise 1: Create a Project, a Package and a Program in ADT
Lesson: Analyzing and Using A CDS View
Exercise 2: Analyze a CDS View and Use It in Open SQL
Unit 2:
44
51
56
Unit 3:
80
87
93
101
107
109
116
121
126
137
143
145
153
161
169
181
188
197
203
213
Basic SQL Features in CDS Views
Lesson: Define a Simple CDS View
Exercise 3: Define a Simple CDS View
Lesson: Creating a CDS View with Inner Join, Projection, and
Selection
Exercise 4: Define a CDS View That Reflects a Database View
Lesson: Using ABAP Annotations in CDS Views
Exercise 5: Use Annotations in DDL Sources
61
67
73
79
Introduction
More SQL Features in CDS Views
Lesson: Using SQL Expressions in CDS Views
Exercise 6: Use Expressions in a CDS View
Lesson: Using Built-in SQL Functions in CDS Views
Exercise 7: Use Built-in Functions in a CDS View
Lesson: Understanding Nested Views
Exercise 8: Define a CDS View based on other CDS Views
Lesson: Using Aggregations in CDS Views
Exercise 9: Define a CDS View with Aggregation
Lesson: Using Additional Join Types and UNION (ALL)
Exercise 10: Define a CDS View with a UNION statement
Unit 4:
Advanced Concepts
Lesson: Defining CDS Views with Input Parameters
Exercise 11: Define and Use a CDS View with Input Parameter
Lesson: Building CDS Views with Associations
Exercise 12: Define a CDS View with Associations
Exercise 13: Use a CDS View with Associations
Lesson: Enhancing a CDS View
Exercise 14: Enhance a CDS View
Lesson: Linking a CDS View with Authorization Rules
Exercise 15: Create and Use a DCL Source
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v
219
Unit 5:
220
231
241
242
249
253
260
264
269
vi
Database-Specific Features of ABAP CDS
Lesson: Understanding CDS Table Functions
Exercise 16: Define and Use a CDS Table Function
Unit 6:
Consumption of CDS Views (Outlook)
Lesson: Using a CDS View as Data Source for ALV IDA
Lesson: Using CDS Views as Replacement Objects
Lesson: Generating OData Services from CDS Views
Lesson: Understanding the Consumption of CDS Views in SAP Fiori
Lesson: Understanding Analytics Based on CDS Views
Lesson: Understanding Virtual Data Models with CDS Views
© Copyright. All rights reserved.
Course Overview
TARGET AUDIENCE
This course is intended for the following audiences:
© Copyright. All rights reserved.
vii
viii
© Copyright. All rights reserved.
UNIT 1
Introduction
Lesson 1
Motivating CDS Views and Understanding the Background
2
Lesson 2
Working with ABAP Development Tools (ADT)
Exercise 1: Create a Project, a Package and a Program in ADT
14
19
Lesson 3
Analyzing and Using A CDS View
Exercise 2: Analyze a CDS View and Use It in Open SQL
23
35
UNIT OBJECTIVES
●
Know the Background for Core Data Services
●
Understand the Basics of CDS
●
Work with ABAP Development Tools
●
Read a Data Definition
●
Use CDS-related Tools in ADT
●
Use Open SQL to Read From a CDS View
© Copyright. All rights reserved.
1
Unit 1
Lesson 1
Motivating CDS Views and Understanding the
Background
LESSON OBJECTIVES
After completing this lesson, you will be able to:
●
Know the Background for Core Data Services
●
Understand the Basics of CDS
SQL Basics and ABAP's Classical Approach
When it comes to accessing a Database Management System (DBMS) from within an
application programming, the Structured Query Language (SQL) has established itself as a
kind of first choice. SQL is largely standardized as ANSI SQL, but each vendor adds its own
features.
Structured Query Language {SQL)
- Access to database management systems (DBMS)
- Largely standardized (SQL-92)
- Three sublanguages: DML, DDL, DCL
1
• Data Mani,pulatlon Language (D ML)
- Read and change data in DB tables
- Statements SELECT, INSERT, UPDATE, DELETE ...
• Cata Definition Language (DDL)
- Create and ma.intain DB tables and views
- Statements CREATE, ALTER, DROP, ...
Data ,control Language (DCL)
- Define authorizations and transaction control
- StatementsGRANT, REVOKE, ...
]
Figure 1: Reminder: SQL Overview
SQL as a whole covers all kinds of tasks that might be relevant for an application program.
There are three sublanguages of SQL:
Data Manipulation Language (DML)
Provides statements for reading and changing the content of database tables and
comprises statements like SELECT, INSERT, UPDATE, and DELETE.
Data Definition Language (DDL)
2
© Copyright. All rights reserved.
Lesson: Motivating CDS Views and Understanding the Background
Provides statements for creating database objects like tables and views and to maintain
their properties. Statements like CREATE TABLE, CREATE VIEW, ALTER TABLE, DROP
TABLE belong to the DDL part of SQL.
Data Control Language (DCL)
Covers the aspects of data integrity and security. DCL allows the application to define
authorization rules and to bundle DML statements into transactions (better known to the
ABAP developer as Logical Units of Work (LUW). DCL statements are, for example,
GRANT and REVOKE.
ABAP had always had a very special approach to SQL.
ABAP's Classical Approach to SQL
OML inABAP
- Open SOL, integrated in programming language
- DB-independent syntax
- DB-independent behavior
- Reduced feature set compared to SQL-92
• DDL inABAP
- ABAP Dictionary
- DB-independent tool
- Form-based editing of table definitions and views
DCL inABAP
- Not needed in ABAP
- Authorization and transaction control never on DB level
- Always done in application (AUTHORITY-CH ECK, COMM IT WORK, ... )
]
Figure 2: ABAP's Classical Approach to SQL
In principle, only the DML part of SQL is available to an ABAP program at runtime. Open SQL,
SQL
the SQL variant that is built-in into the ABAP language, only covers DML aspects.
When ABAP developers want to define database tables and views, they are not supposed to
issue DDL statements at runtime. They have to use the ABAP Dictionary tool, which provides
form-based editors for table and view definitions (for example, repository objects
Transparent Table and Database View). During activation of these definitions, the system
creates database-specifc DDL statements and sends them to the database.
The DCL part of standard SQL is not needed in ABAP. In the classical approach of ABAP, all
tasks covered by this sublanguage are kept away from the database. The ABAP application
logic is supposed to take care of authorization checks, locks, and transactions (LUWs).
The Limitations of Classical Open SQL
Open SQL not only restricts itself to the DML part of SQL. When we look at standard SQL, for
example, the SQL-92 Standard, many DML features described there are missing from Open
SQL.
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3
Unit 1: Introduction
Limirtations in .ABAP < 7 .4 SP05
SQL-92 Standard
.,.
AMitio�al
restrictwl'\S
Open SQL
(before ABAP 7.4)
Figure 3: Limitations of Open SQL Before Release 7.40
Among the many limitations of conventional Open SQL, the missing support for expressions,
either in the field list or in the WHERE clause, was the most obvious and most dearly missed
by application programmers.
• General Restrictions
- No fixed values
- No computed values
No CASE expressions
- No SQL tu notions
1
limited Support for J o·i ns
- Only inner joins and left outer joins
- Only Equi.Joins fjoin condition with operator "=" )
- In left outer join: No fields of right table in WHERE clause
More limitations
- No UNION or UNION ALL
I
Figure 4: Some Limitations of Open SQL Before Release 7.40 SP05
Two important reasons exist for these limitations:
Open SQL wants to be database-independent, not only regarding syntax but — much more
important — regarding the results. Open SQL has to be guaranteed that an Open SQL
statement provides the same result on all databases. The easiest way to do this is to avoid
those features of standard SQL where the database vendors have different opinions about
what the result should look like. One example are arithmetic expressions where rounding
rules are not the same on all databases.
A basic performance rule of ABAP Programming has always been: Keep unnecessary load
away from the database. The general assumption had been, that an application
programmer, by following this rule, would not make too much use of more sophisticated
SQL features, even when they were available in Open SQL.
The Limitations of ABAP Dictionary Views
When it comes to the definition of Views in the ABAP Dictionary, the gap between ABAP and
standard SQL used to be even bigger.
4
© Copyright. All rights reserved.
Lesson: Motivating CDS Views and Understanding the Background
• DB-indepe,ndent Definition of Database View
- Defined in ABAP Dictionary (form based tool)
- Created on database (CREATE VIEW statement)
Very limited support o,f SQL features
Only inner joins with Equi-join
Only simple projections (no calculated fields, no conversions, functions, ... )
- Only simple selections (using literal values)
- Only DB tables as source (View-on-View not supported)
Some ABAP specialities
- Buffering
- Labels (through data elements)
- Search helps and foreign key relations (inherited from underlying tables)
Figure 5: ABAP Dictionary Views
ABAP Dictionary Views
Support on all DBMSs
Join/Union. Projection. Selection
inner join & simple
selection only
x
Calculation expressions, aggregation, grouping
not supported
��Wfrr1.1
Nested views ( on views)
x
not supported
I
I I
Figure 6: Limitations of ABAP Dictionary Views
Again, the main reasons were the common ground for all supported databases and the
general “Keep load away from the database” approach.
SAP HANA and the Need for Code-to-Data
This all changed when, starting with Release 7.4, SAP HANA was fully supported by ABAP
systems.
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5
Unit 1: Introduction
SAP HANA takes advantage of
the latest technology
developments
100''/o
In-Memory computing
OLTP II OLA� In rt!a�llm!!
Column and rCNv storage
And changed the way of
developing and executing
applications
No
Less
Aggregates
OD-the-fly data models
v.illoutdupk-ilt�
Indices
Fleiwle
aml fut
relrievel ofthe dalasel
Compression
�1L
[
Text Milllg
83�� on c:olurnn !il<lrag�
I
10-10,000x
Acceleration
Mas...;.e parallemlion
Less
Parti-
tioning
Code lines
L�!:c:ornplt!.'d.y In
data mod@k and code
Mass data
analysis
Ana�/
Tra�ction
Figure 7: The SAP HANA platform - More than just another database
With SAP HANA, SAP combines the latest developments in hardware and software
technology to provide a state-of-the-art in-memory database.
However, SAP HANA is much more than a database. Several data analysis engines and a builtin application platform allow the execution of detailed data analyses and even application
logic on the database layer itself.
To benefit the most from SAP HANA's capabilities, it is necessary to change the programming
paradigm as well as the traditional application design.
•
ApplicaUon
Programming
Models
Database
Figure 8: Paradigm Changes in Application Programming
The basic approach of classic ABAP programming was:
6
●
Keep load from the database
●
Get all the data you need on the application server, and
●
Do your processing in ABAP
© Copyright. All rights reserved.
Lesson: Motivating CDS Views and Understanding the Background
But to benefit the most from SAP HANA's capabilities, especially from its use of parallelism
and optimized data structures and transfer, it is better to do expensive calculations and
aggregations on the database itself rather than transferring huge amounts of data onto the
ABAP application server. This is a fundamental change to the ABAP programming paradigm.
Now it becomes "logic to data", or "code-to-data" as it is frequently coined, rather than "data
to logic".
Classic Applications
UI Rendering
Data-Centric Applications
Presentation Server
UI & Client
Side Application Logic
U I Application Logic
Service Logic
Application Server
Data-Centric Logic
Database
Relallonal
D
SAP HANA
Database
*Service Layer on Application Server or on SAP HANA itself (SAP HANA XS)
Figure 9: Transformation of Application Design
The classical design of ABAP applications combined a powerful application server with a
relatively dumb relational database and a similarly simple presentation layer. All the logic was
located on the application server.
The new application design, inspired by SAP HANA's improved capabilities, transfers part of
the logic (called Data-Centric Logic in the figure above) onto the database. On the other end,
big parts of the logic (called UI Application Logic in the figure) move from the application
server into smart clients.
Only a middle part of the overall logic (Service Logic) remains on an application server.
Note:
It is even possible to implement this remaining service layer on SAP HANA itself. This
approach is used by SAP HANA XS.
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7
Unit 1: Introduction
SAP HANA Core Data Services
UI Rendering
UI & Client
Side Application Logic
UI Application Logic
Service Logic
Data-Centric Logic
Database
SAP HANA platform
Figure 10: SAP HANA Native Applications and the Need for CDS
With the dawn of SAP HANA and the possibility to develop applications directly on the
database, not using an application server any more, the need arose to create a meta model
repository directly on the database. As with the ABAP Dictionary on the application server,
there should be more in the box for you than using native SQL's CREATE TABLE or CREATE
VIEW. Especially regarding the need of enriching pure technical definitions with semantics.
And that's one of the main reasons for SAP's Core Data Services.
The Core Data Services (CDS)' are a collection of domain-specific languages and
services for defining and consuming semanticallly rich data models.
DDL
Data Definition
Language
Model and retrieve data
on a semantic level
higher than SQL
QL
Query Language
Consume CDS entities
Fully transparent SQL
extensions
Extends native SQL
means for increased
productivity
DCL
Data Control Language
Define authorizations for
CDS views
Modelled and declarative
approach
Integrates with classic
authorization concepts
Figure 11: Concept of Core Data Services (CDS)
There are many technologies that introduce higher-level models on top of SQL to add
semantics and ease consumption – for example, OData EDM models, the Semantic Layer in
the BI platform, JPA and enterprise objects in Java, or the business objects frameworks in
ABAP. Those higher-level models share many commonalities, but are usually specific to their
technology. This prevents their reuse across stacks and increases effort for application
developers.
8
© Copyright. All rights reserved.
Lesson: Motivating CDS Views and Understanding the Background
To address this, SAP HANA introduced a set of domain-specific languages (DSL) and services
– called Core Data Services – for defining and consuming semantically rich data models.
Among these languages is an enhanced Data Definition Language (DDL) for defining
semantically rich database tables/views (CDS entities) and user-defined types in the
database.
Some of the enhancements are:
Expressions
Used for calculations and queries in the data model
Associations
On a conceptual level, replacing joins with simple path expressions in queries
Annotations
To enrich the data models with additional (domain specific) metadata
ABAP Core Data Services
UI Rendering,
UI & Client Side
Application Logic
U I Application Logic
Application Server ABAP
Service Logic
Application Logic (ABAP)
Data-Centric Logic
Database
Database Schema
(Any) Database
Figure 12: Core Data Services on ABAP
From the beginning, CDS was not designed for SAP HANA alone. Also the ABAP application
server should be able to benefit from the enhanced capabilities that are offered by the DDL of
CDS compared to the form-based ABAP Dictionary tool.
Since the ABAP Dictionary with its capability of defining tables, views, and data types was
already there, the natural way of introducing CDS on the ABAP application server was to add
it to the ABAP Dictionary.
An ADT-based source code editor allows you to create DDL sources. On activation, the CDS
entities defined in such a DDL source become full citizen ABAP Dictionary objects. They work
as ABAP types that can be named after a TYPE addition and they can be accessed in Open
SQL.
© Copyright. All rights reserved.
9
Unit 1: Introduction
Database Independent
- Use CDS ABAP with any database supported by SAP
Advanced View Bui I ding
- CDS Views provide m uoh more SOL features than classical Dictionary Views
Annotations to add Semantic: Information
- Add end user texts, currency keys, buffer settings, ...
- Add semantic information for consumers (ana.lytics, OData, SAP Ul5, ... )
• Implicit.Authorization Checks
- Define authorization rules for CDS Objects
• Associations instead of Joins
- Define relations between CDS Objects that will be transleted into joins
• CDS Table Functions
- Views based on scripted coding [Currently only supported for SAP HANA)
I
Figure 13: Some Basic Features of ABAP CDS
As a first step, the advanced view building capabilities of CDS have been implemented in
ABAP CDS. With many, many tables already defined in the ABAP Dictionary, the DEFINE
VIEW statement of ABAP CDS makes the full wealth of the CDS universe readily available to
existing ABAP data models.
You can either define sophisticated new views or simply wrap an existing table in a CDS view
in order to enrich it semantically. For example, ABAP CDS offers a new authorization concept
based on roles defined with DEFINE ROLE in a DCL source code. In order to let an existing
table participate in the new authorization concept, you can simply create a CDS view for that
table that is connected to a role. Other examples are advanced joining of tables with
associations or using specific annotations in order to connect existing tables to new
technologies like OData or UI5.
10
© Copyright. All rights reserved.
Lesson: Motivating CDS Views and Understanding the Background
ABAP Diictionary Vi:ews
ABAP'
cos Views
Support on all DBMSs
Join/Union, Projection, Selection
111? I
1::c:--1111
inner join & simple
selection only
x
1
inner join. outer
Join, union
Calculation expressions, aggregation, grouping
not supported
Nested views (on views)
x
not supported
Figure 14: Advanced View Building with CDS ABAP
On a purely technical level, ABAP CDS Views provide the following additional capabilities
compared to ABAP Dictionary Views:
•
●
Enhanced support for combining queries, such as UNION and OUTER joins
●
Support for calculations that use expressions in the column list and for selection
●
Aggregation and grouping in the data model
●
Nested views (View-on-View)
Two Ways of Database Integration
Even so the Core Data Services SpecificatiOn is language and platform agnostic,
the CDS implementations are not.
BAP
•
D
Same Semantic on alll DBs
• Initial Focus on View building
• Integration into ABAP Dictionary
NA
•
O
IHAINA only
(HANA specific features available)
• Initial Focus on Building Models
from Scratch
Figure 15: ABAP CDS versus HANA CDS
With HANA CDS and ABAP CDS we have two implementations based on the same
specification. They are very similar but not 100% equal. This is mainly because the two
implementations pursue different goals:
© Copyright. All rights reserved.
11
Unit 1: Introduction
HANA CDS is located on the SAP HANA database directly and is meant to support the
development of SAP HANA native applications (SAP HANA XS). It makes liberate use of
features which are unique to SAP HANA.
ABAP CDS is located on the Application Server ABAP, where it is fully integrated in the ABAP
Dictionary and thus in the ABAP transport system, lifecycle management, etc. The goal of
ABAP CDS is to support the implementation of ABAP applications – independent of the
database system. Therefore its initial focus is on view building, and not on building models
from scratch – although this might become possible in the future.
Conclusion:
Due to the different requirements and platforms, the two CDS implementations have different
feature sets and release cycles. A technical compatibility is not guaranteed.
CDSelated Repository Objects
Ill
Data. Definition (DDL Source)
- Defines a COS View or CDS Table Function
- Display-only in ABAPWorkbench (as olf Rel. 7.51)
- Editing requires the use of ABAP Development Tools
(ABAP in Eclipse)
• Access Control (DCL Souree)
- Defines authorization rules that are automatically
checked when a program reads certain data
- Display-only in ABAPWorkbench (as off Rel. 7.50)
- Editing requires the use of ABAP Development Tools
(ABAP in Eclipse)
Figure 16: CDS-related Repository Objects
With ABAP CDS, the following new repository object types were introduced:
Data Definition
●
●
Also referred to as DDL Source (for Data Definition Language, named after the DDL
part of SQL)
Contains the definition of either a CDS View or a CDS Table function
Access Control
●
●
12
Also referred to as DCL Source (for Data Control Language, named after the DCL part
of SQL)
Contains the definition of authorization rules that are automatically checked when a
program accesses a certain CDS View or CDS table function
© Copyright. All rights reserved.
Lesson: Motivating CDS Views and Understanding the Background
Note:
Depending on the system release, you can display the source code of the new
CDS-related repository objects in the classical ABAP workbench. However, to
create or change the new repository objects, you have to use the respective
editors in ABAP Development Tools (also known as ABAP in Eclipse).
LESSON SUMMARY
You should now be able to:
●
Know the Background for Core Data Services
●
Understand the Basics of CDS
© Copyright. All rights reserved.
13
Unit 1
Lesson 2
Working with ABAP Development Tools (ADT)
LESSON OBJECTIVES
After completing this lesson, you will be able to:
●
Work with ABAP Development Tools
Eclipse-Based ABAP Development
ABAP Development Tools (ADT) is an alternative to the ABAP Workbench. ADT provides the
following features:
●
A complete new ABAP development experience on top of the Eclipse platform
●
An open platform for developing new ABAP-related tools
●
A set of open, language-independent, and platform-independent APIs that developers can
use to build new custom tools for the ABAP environment
SAP GU I Cliient
Ec'lipse Client
ABAP Development
I
Tools (ADT)
NWASABAP
(7.31 SP4 or higher)
.--��-.aL���-,
ABAP
Workbench
-���---��-....
Repository
Figure 17: ABAP Development Tools — Eclipse Based ABAP Development
Benefits of Developing in Eclipse
With ABAP Development Tools in Eclipse, you benefit from the usability, speed, and flexibility
of Eclipse, while also benefitting from proven ABAP Workbench features. ABAP Development
Tools improves developer productivity by offering better refactoring functionality, code
completion, auto-insertion, and code templates. It also includes an invaluable Quick Fix
feature and is highly navigable.
14
© Copyright. All rights reserved.
Lesson: Working with ABAP Development Tools (ADT)
ABAP Development Tools allows you to connect to multiple ABAP systems and provides
session failover, reducing the impact of lost connections. It also enables cross-platform
development by integrating ABAP and non-ABAP development tools in a single, powerful
integrated development environment (IDE).
The architecture of ABAP Development Tools for SAP NetWeaver is designed to allow
developers to use a single Eclipse client, installed locally, that connects to several ABAP backend systems of different releases. This allows developers to control all activities in a central
location and helps avoid time-consuming context switches. The client provides a set of
standard Eclipse development tools, such as the project explorer for system browsing and
search views.
Getting Started with ADT
• l!fl
•
Eclipse is a framework
• Too.lls for different languages as plugins
•
Each "Perspective" defines a set of tools
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Choose Perspective 11ABAP11 for
ABAP Development
Figure 18: Selecting the Perspective
Eclipse allows development in many different programming languages. To support this,
Eclipse contains different combinations of tools, called Perspectives. If you have ADT
installed, you can switch to the ABAP perspective. Choose Window→ Open
Perspective→ Other...→ ABAP in the menu bar or choose the Open Perspective button.
© Copyright. All rights reserved.
15
Unit 1: Introduction
• ARIAP • E chpse
-IN'i>rf�,.
• AIIAPl'l'09flll'n
a.kN
Oful!I •• •
ABAP Project: Logon to one ABAP System
(System ID, Client, User and Password)
1
Favorite Pac kages per ABAP Proj,ect
1
Multip,le ABAP Projects i n one Eclipse
Figure 19: Creating a Project
When you use ADT, you log on to an SAP back-end system and work directly with its
repository objects. In this sense, the development process is exactly the same as when you
use the ABAP Workbench, there is no manual check-out and check-in of the objects.
An ABAP project serves as a container for the development objects that are stored in a
particular ABAP back-end system, and contains the logon parameters for the system logon —
System, Client, User, and language. You must be logged on to the system to edit an object.
Within the ABAP project, you can access any development object in the repository. In
addition, to make it easier to manage objects you can set up favorite packages for each
project.
Editing Repository Objects in ADT
Syntax Check
Test (in SAPGUI window)
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pa_ .. ..,,,., TYPE sr.,: ing.
H�lJo 110.:-Jd.! •.
1
'Ii llc>',
pi,,_�-
-
ss
Sy>lemlh"'Y
T abstrirp to quickly
navigate 'between
editors I objects
Double-Click to
open in editor
-----=========�======-�
�
Figure 20: Editing Repository Objects
16
© Copyright. All rights reserved.
Lesson: Working with ABAP Development Tools (ADT)
The Project Explorer provides a hierarchical view of the repository, similar to the navigation
area of the ABAP workbench. Under each project, you can maintain a list of favorite packages.
By expanding the node System Library, you see a list of all packages.
To open a specific repository object in its respective editor, double-click it. The editor is
shown on the right side of the ABAP perspective. For each new object, a new tab is added.
This simplifies the navigation between editors and objects.
•
Different Types of Editors
Native Eclips,e Editors
'9
IZMEJZIIC@III_IL ti
Q.
[ZMEJ2ilCIIOII_D_
[�EJ2.J:IC4.0t_.-
r
IZMU:!il'Fll
c:1
C]
• ,_ --- ---- --- ------------------ ------- -------------- ------- ------------. '..J
• Eclipse features
::
i;i,e:�rii:
llt:'100_�:!J_HZ:t.l.O
•••••••••-•••• ••••••
····--··-•••••••••••
• Available for some
Repository Objects
(e.g. Pmgrams,
Classes
Web Dynpro, etc. )
'Wi!:IT'!l":tlll!IJ.i.illQll"lllll'.
tZ:!IJ•LDr!:.
;wJ!Jff:
• Eclipse-like look & feel
·n,uo·.
:J;llll!li_illllllol.
.!.I
Integrated SAP GUI Ediitors
O,JVq,_......_.,mo
�IZlo'EJ-.M.�I\LQ 11
� 6'
• <l
eee
,, C
1.IIIM
t'lt'ld.Hl
D/1pJ�y R.#Port Tr!IIIHai.fi!n
• SAP GUI Look & Feel
� .. '$''!3 /11,l!!I� .l'l.!100
�oi;JJ1Ul.Q
ll!i;.tOiO_O(I
-...
-. r
..,,,
• No new features
l!I "
------i
tst"«-D (l{J_�J.'l.O
r,...,
• Used where no native
editor is available
(e.g. Transactions,
Dicti,onary Objects,
screens, etc.
Figure 21: Native Editors or Integrated SAP GUI Editors
There are two kinds of editors in ADT – there is a native Eclipse implementation and an SAP
GUI based implementation. In the figure, Native Editors and Integrated SAP GUI Editors, you
can see an example of each of the following types:
There are two types of editors in the ABAP development tools:
●
Editors for which there is a native Eclipse implementation
For example, ABAP Editor
●
Editors that are displayed in an in-place SAP graphical user interface (GUI)
For example, ABAP transaction editor with the classic SAP GUI visualization appearing
within the Eclipse environment
There is no requirement to use ADT for ABAP Development, and each developer is free to
choose whether to use ADT or the classic ABAP Workbench. The functions and features of
Eclipse and ADT lend themselves particularly well to object-oriented programming, among
these features are various built-in refactoring functions and support for unit testing. There are
other tasks to which the ABAP Workbench is better suited — in particular working with
module pools and screens.
© Copyright. All rights reserved.
17
Unit 1: Introduction
Documentation, Installation and Support for ABAP Development Tools
GetABAP Development Tools from:
SAP Software Downl,oad Center
• http:1/service.s.ap.com/swdc
SAP Devellopment Tools for Eclipse
� SAP OevelopmeAt lools lor EclQl5e
HOME
ABAP TOOLS
CLOUD TOOLS
GATEWAY TOOLS
This slte allows )'CU to lnslallvarious SIIP CfeVelopme11ttools pacltaoes lor Ed,pse.
Note tlll3t some ttols are only avauat,le tor Edjpse Juno but not ret1or Edlpse Kepler.
somvare Sit&s
• http:1/tools.hana.ondemarid.com
Also see SAP Community Network
• htt�:l/scn.sap.com/comm11.111ity/abap/
eclipse
To install som� or au ol1Mtoo1s 11s�e<1 i:,erow. g�tS'iP HAN1, Stud o oran Edlpse Ins
/lllitailNewsom,·.rte �I'll:
For S::P HWASlill1iP and E!dlips11Jun� (<l.2). add lil11 URLWlil�ll!l!li!.I.Lil1!.ll..llj
• for Eclipse Kepler(4.3). add lile URL.tl.!!IIU!l!�.billi.gj]IW!lill.l!m!DW!i.lil
Figure 22: Further Information
If you are looking for a local installation of ADT, you can choose from the following sources:
●
●
●
18
SAP Software Download Center (http://service.sap.com/swdc), a part of the SAP Service
Marketplace.
SAP Development Tools for Eclipse Web site (http://tools.hana.ondemand.com). You can
also find other products, such as the SAP HANA studio or the tools for SAP UI5
development on this site.
SAP Community Network pages (http://scn.sap.com/community/abap/eclipse and
http://scn.sap.com/community/abap/hana). They provide documentation and support
on how to install the SAP Development Tools for Eclipse.
© Copyright. All rights reserved.
Unit 1
Exercise 1
Create a Project, a Package and a Program in
ADT
Business Example
Template:
S4D430_INTRO_T1 (Executable Program)
Solution:
S4D430_INTRO_S1 (Executable Program)
Create a new ABAP Project in ADT
Open ABAP Development Tools. Create a project for application server S4D and add package
DEVS4D430_EXERCISE as a favorite package under this project.
1. Open ABAP Development Tools, that is start Eclipse and open the ABAP perspective.
2. Create a project connected to system S4D. Use client, user ID and password provided by
your instructor.
3. Add package HA400_PRIMDB_EXERCISE to the favorites of this project.
Create a Package with ADT
In your project, create a new development package Z4D430_## (where ## stands for your
group number) and add it to the favorite packages in your project.
1. In ADT, create a new development package Z4D430_## (where ## stands for your group
number).
2. Add your package Z4D430_## to the favorite packages under your project.
Create and Test a Program with ADT
In ADT, create a copy of executable program S4D430_INTRO_T1 and place it in your package.
De-comment the source code in the program. Perform a syntax check, then activate and
execute the program.
1. Create a copy of executable program S4D430_INTRO_T1 (suggested name for the copy:
Z##_INTRO, where ## stands for your group number) and place the new program in your
package Z4D430_##.
2. In your new program, de-comment the entire commented source code.
3. Perform a syntax check for your program.
4. Activate the program.
5. Perform a test of the program as ABAP application (SAP GUI application) from within
ADT.
© Copyright. All rights reserved.
19
Unit 1
Solution 1
Create a Project, a Package and a Program in
ADT
Business Example
Template:
S4D430_INTRO_T1 (Executable Program)
Solution:
S4D430_INTRO_S1 (Executable Program)
Create a new ABAP Project in ADT
Open ABAP Development Tools. Create a project for application server S4D and add package
DEVS4D430_EXERCISE as a favorite package under this project.
1. Open ABAP Development Tools, that is start Eclipse and open the ABAP perspective.
a) Choose Start→ All Programs→ Eclipse from the Microsoft Windows Start Menu.
b) If the Welcome page is open, close it or choose the Workbench link.
c) Change to the ABAP perspective using the push button in the upper right-hand corner.
2. Create a project connected to system S4D. Use client, user ID and password provided by
your instructor.
a) Right-click anywhere in the Project Explorer window on the left and choose
New→ ABAP Project.
b) Click the Browse button and choose system connection S4D. Press OK followed by
Next >.
c) Enter client, user and password given to you by your instructor. Choose Finish .
3. Add package HA400_PRIMDB_EXERCISE to the favorites of this project.
a) In the Project Explorer, expand the project. Right click Favorite Packages under your
project and choose Add a Package....
b) Enter package name DEVS4D430_EXERCISE and press OK.
Create a Package with ADT
In your project, create a new development package Z4D430_## (where ## stands for your
group number) and add it to the favorite packages in your project.
1. In ADT, create a new development package Z4D430_## (where ## stands for your group
number).
a) In the Project Explorer on the left, right-click your project and choose New→ ABAP
Repository Object ....
20
© Copyright. All rights reserved.
Lesson: Working with ABAP Development Tools (ADT)
b) In the dialog window New ABAP Repository Object expand node Package, choose entry
Package and click Next.
c) On the next dialog window, enter Z4D430_## (where ## stand for your group number)
and choose Next.
d) On the next dialog window, enter a Short Description for your package and choose
button Continue (Enter).
e) On the next dialog window, choose Own Requests to select the prepared transport
request.
f) Choose Continue (Enter).
2. Add your package Z4D430_## to the favorite packages under your project.
a) In the Project Explorer, right click Favorite Packages under your project and choose
Add a Package....
b) Enter the name of your package and press OK.
Create and Test a Program with ADT
In ADT, create a copy of executable program S4D430_INTRO_T1 and place it in your package.
De-comment the source code in the program. Perform a syntax check, then activate and
execute the program.
1. Create a copy of executable program S4D430_INTRO_T1 (suggested name for the copy:
Z##_INTRO, where ## stands for your group number) and place the new program in your
package Z4D430_##.
a) In the Project Explorer, Expand your favorite package DEVS4D430_EXERCISE. You
find the executable program under Source Code Library→ Programs
b) Right-click on the template program and choose Duplicate....
c) Enter the name of your package (Z4D430_##) and the name for the new program
(Z##INTRO) and choose Next>.
2. In your new program, de-comment the entire commented source code.
a) Left-click anywhere in the source code.
b) Hit keys Ctrl+a to mark the entire source code.
c) Hit keys Ctrl+> to de-comment the entire source code.
3. Perform a syntax check for your program.
a) Choose push button Check ABAP Development Object or hit keys Ctrl+F2.
4. Activate the program.
a) Choose push button Activate or hit keys Ctrl+F3.
5. Perform a test of the program as ABAP application (SAP GUI application) from within
ADT.
a) From the menu, choose Run→ Run As→ ABAP Application or hit key F8.
© Copyright. All rights reserved.
21
Unit 1: Introduction
LESSON SUMMARY
You should now be able to:
●
22
Work with ABAP Development Tools
© Copyright. All rights reserved.
Unit 1
Lesson 3
Analyzing and Using A CDS View
LESSON OBJECTIVES
After completing this lesson, you will be able to:
●
Read a Data Definition
●
Use CDS-related Tools in ADT
●
Use Open SQL to Read From a CDS View
DDL Source SQL View and CDS View
DDLSource
Dictionary object,
contains definition of
SOL View and CDS View
/:nerated
upon
tivation
I'
\.
SQLView
Dictionary Object,
Represents Database Object
r
....
CDS View Entity
Neither in Dictionary nor on Database,
Carries more semantic,
Figure 23: One DDL Source – Defines Two Objects
A CDS View is defined in a DDL Source, which is a new type of repository object. There is no
editor for DDL sources in the classical ABAP workbench. This new type of repository object
has to be analyzed and developed in ABAP Development Tools in Eclipse.
Upon activation of a DDL Source, two objects are created: the SQL View and the CDS View.
Neither of them can be edited directly.
The SQL View is visible as an object in the ABAP Dictionary where it cannot be edited and only
reveals a fraction of the information available in the DDL source. It serves as a representative
of the database object.
The CDS View carries more semantics than its SQL view. It is not created on the Database and
it is not visible in the ABAP Dictionary. It can, however, be consumed via open SQL. The new
Open SQL syntax introduced with NW 7.40 SP5 is required to access CDS Views.
© Copyright. All rights reserved.
23
Unit 1: Introduction
Annotation:
@AbapCatalog.sqlViewName: 'S4D430_CARR'
define view S4D430,_Carrier as select carrid1
carrname,
currcode,
url
from sear-r
Name of �he
SQL View
Fielld list {comma
separated)
Name of the
CDS View
FROM cllause
Figure 24: SQL View and CDS View in DDL Source
As with conventional database views, the simplest form of a CDS view is a projection – that is,
a selection of fields from a single table.
The language used is SQL Data Definition Language (DDL), but in an Open SQL form so that
the view can be deployed on any database platform. As CDS views are part of Open SQL,
notice also that there is no explicit client handling.
l
l
DDL Source
-,
./
[
SQL View
J
SQL View ...
,
CDSVlew ..
CDS View ...
Repository Object (Dictionary}
• Not found in repository
Represents "real" database object
• Not known to database
Is an ABAP data type
• Is an ABAP data type
(structure, with client field)
, No additional semantics
I
[
(structure, without a client field)
• Additional semantics (Annotations)
Figure 25: Difference Between SQL View and CDS View
The name of the CDS entity is specified after the DEFINE VIEW statement. It is recommended,
though not technically necessary, that the name of the DDL source and the name of the CDS
view are identical.
The name of the SQL View is specified after the Annotation @ABAPCatalog.sqlViewName. It
has to be different from the name of the CDS entity. Like for any Dictionary view, the
maximum length is 16 characters.
24
© Copyright. All rights reserved.
Lesson: Analyzing and Using A CDS View
Annotations
@AbapCatalog.sqlViewName: 'S4D430_CARR'
@Abapcatalog.compiler.compareF·lter: tr�e
@Accesscontrol.authorizat·oncheck: #CHECK
@EndUserText.label: 'Demo: Simple Projection'
View Annotations
Element Annotation
before the element
define view S40438_cairrier a,s
select carrid,
carrname;
@EndUserText. label: 'Currency Code'
currcode�
Element Annotation
after the element
url @<EndUserText. label: 'Homepage'
from scarr
Enri:ch a definition with metadata
Start with character"@"
May be related to the complete view (view annotations)
or to individual parts (element annotations, parameter annotations. etc.)
Are mostly optional (exception: @AbapCatalog. sql.ViewName)
Figure 26: Annotations – Some Basic Facts
A CDS annotation (or annotation for short) enriches a definition in the ABAP CDS with
metadata.
An annotation is identified by a simple or structured name after leading character "@" or
"@<".
Depending on its scope, an annotation can be found in different locations within the CDS
Source.
View annotations
Relate to the view itself and are placed before the define view statement.
Element annotations
Relate to elements in the field list and can be found before or after the element.
[o
Hint:
Element annotations after the element begin with leading characters "@<" .
SAP uses a set of predefined SAP annotations. Most of them are optional. But there is one
exception: @AbapCatalog.sqlViewName is mandatory in every CDS View definition.
© Copyright. All rights reserved.
25
Unit 1: Introduction
CDS-Related Tools in ADT
• Navigation from SQL View to DDl Source
• Display of SQL CREATE Statement
• Active Annotations View
• Graphical Editor
• Dependency Analyzer
• Data Preview
I
Figure 27: CDS-Related Tools in ADT
ABAP Development Tools offers a variety of tools to analyze an existing DDL Source. These
tools help to understand a CDS view definition – even when you do not yet know how to read
the DDL Source itself.
You find most of these tools if you right click the view name (either in the Project Explorer or
in the DDL Source text) and go to submenu Open With.
Navigation from SQL View to DDL Source
" i:I
v
OEVSAO,:l30(pnty 1 ... dod)
S 0E.VS41)4lO_DEMO
Care D .ta Suvic!:!li
Right-Click the
SOL View
Choose
Open With
-> Definition
D,�ione,y
v. ....
��o·
"JI! SdD4lO.,AGC\'�
"61 Sr��
DEJ!�::::-EM j� New1Dl�on1eyV.ew
> ffl
> IEI: H'A4(i(I
) 19
•
Op•n
I-IA400_(0l�_DE
C'bl+5hilt•G
i. ..
g;,0u1r
!::I
An <Mli�i<.,ot ov•if_.br,.
I
Shor·•Linl<..
A<ti,,,a•:c:
II, Che119eP•d:.,geAi;:ignment
Ron A<
Ocbu,gA,
Poofir.ecA<
_.
U..lo<k
Ct.t•U
Synducn;,ow,th HANA R.opo,;;ta,y
Add llookmaoJ:. .•
Figure 28: Navigation from SQL View to CDS View
If you have located an SQL View and want to know how it is defined, right-click the SQL View in
the Project Explorer and choose Open With→ Definition.
26
© Copyright. All rights reserved.
Lesson: Analyzing and Using A CDS View
Display SQL Create Statement
,1..tiapC.. �alo<,.aql\'.i.e·�I""'"' •stD!!O Cil:RJ.•
@.tJJepCat:alc:io .c:o- :t..lc:: .c:ciccpa::er11t::;;::: t:'u.�
��<;:<1:lll!Con1ao1.01,1i:;J.o�hai:; o:iel.c<:i<': tCl'l:!!CK
4 SEndU�.,,.r.,xe .lab.,l: • llieo,o, S!.J<pl" Pro;tec:cton •
<ll!lf!M
V"l"W S!<H30_C'a"'"'-'""' ·Revell Filo
S.ve
Q
��%;.�::\.{��. smcr
===:=�=:
·='IR·,·c;,_gJUD",
-�<\?:- '"b"RL •sa,n,,• "SC:Ai,ii;"
!'!!;OM
)
Figure 29: Display SQL Create Statement
When you activate a DDL Source, the development environment sends an SQL statement to
the database to create the SQL View. You can display this SQL CREATE statement as follows:
1. Right-click anywhere in the DDL Source.
2. Choose Show SQL CREATE Statement.
The SQL Create Statement is displayed in a dialog window (popup).
Like with any native SQL statement, details of the CREATE statement will depend on the type
of database used by the system.
© Copyright. All rights reserved.
27
Unit 1: Introduction
Active Annotations View
..., "It OEVS:O,l:IOl..-•r'!l)·lo. 111•d
�S!�.CEMO
Right-Click the
'" o ..,s.......
v
i.OmOtM....,.,
ii)�N('l... r�vr,,uE t,
mwm • .,.
!�;'"
mw
:..
,,"Iii--r1@r?.CAPMR o.... s.. ,1,+
-
1
Vit.WS
r,ll�_A(l(YltEY
�SIIM.30.BOOl::,IGO'
r,IISIIM:!O_C_
> ill �,....,,;t,ot.11111_.;ii...lliili'l.l!i!!!l.!.ii-__
�
v..-o��� :i>
��
0.p<nde"')'
""'I),"
>
Ot<�i<lon;i D Gr�Killl&il:or
> II! ,,-oecos.E>ttc1SE
>
itlflrir:0..t:A�t-5
>ll�ml1b,a�
).,,,,., !3
..
�,:, :.,
v'!ll<ol«•
> Oh"'
) =g sdtdlm
o.,,w....io,.
Choose Open
With -> Active
Annotations
.. I
Or,c,,
) ll!lll'IS'OOO.
v
N'...
lkl;plkm..
>lll>WIJC
� :;:�;.
DDL Source
r...
x
�
.
� .,.
"-�·'
lltl ...
Oll<t•
wtW1\ere-idl-dllri.,,N
Opens in Tab
below the editor
�,
Clrl.+itiafh(i.
l@ . ..... -......,tll ..,,
-=-,, .... s.__
I
• i''!,
i\
A<tir.rt"
°""JoPiC"'9"AA'9""'""
�
430_ca,,;,.,,
..
---�·Prcfilc:ilt5,
c,a.11
Cbl,/dt,C >
Annottte:d[lan.fflts
Anno'lil'lioniYllue
T"""'t<dT«t
Si:4,l;W,Cimn
..,w)�iru'l�ici11i
Figure 30: Active Annotations View (1)
The Active Annotations view summarizes the semantic information of the CDS View and of its
view fields.
This is not restricted to annotations alone. It also lists semantic information that is taken
(inherited) from other CDS Views or from DB table definitions and data elements.
Open the Active Annotations view as follows:
1. Right-click DDL Source. (Either in the editor window or in the Project Explorer.)
2. Choose Open With→ Active Annotations.
The Active Annotations view is displayed in a dedicated tab in the tabstrip below the editor
window.
28
© Copyright. All rights reserved.
Lesson: Analyzing and Using A CDS View
Cl P11>p.. b •.., . .,
•:. Pr<lbL
11w1o.
'OJ ,...i. ...
@ ,..m,. t3 � ...i. ...
Cl ftt<L.
. ,,.,_
II MAP..
,,
s.. rch
::a P""J...
A.&AI'••
.,,.
Active Annotaaons for Entity S4d4SO_Garrier
• 5..t«tion
l
s,
Annot,icd IEl<m<nt,
S4.i4JO_,.rri.,
> � En.� umot•tiom
....
(,trrid
qui<
me
Ai,t ... (od•
Aid ....
ID
labfl
hl!ad,ng
l;EndUfOrloot
qui<ldmc
Aid ..�
Ai,t ...
label
lw,ad,r,g
v
II,
5CAiAA
5C.AllR
,CARR
!IRR
Mfflt
'>/RR
Ai�IIIW!
tunmdi!!
l;EndU<erl..i
1.cc,1,
q....:klmc
label
Ai11I�
Label for view field
CARRIO is inherited
from DB table SCARR
Label for view field
CARRIO originates
from data element
Figure 31: Active Annotations View (2)
In the example above, you can see that field carrid of CDS View S4d430_Carrier has a label
“Airline” that is not defined in the corresponding DDL source. This label is taken (=inherited)
from the source field in SCARR and originates from data element S_CARRID with which this
source field is typed.
Graphical Editor
0£\!S40t30 (p.artly looch:dJ
.., $
[)EVS,l.D4JO.mMO
CorcC 1,eScfvicff
Data,Di!linitions
€J S4l)430_AGENCV_wiiM_Rf'l[NUE
Oemo: Trov�i Ag,nry w,:h TOIDI Rev,nu�
(!l �0430.BOO](JNCJ_AND.A.GENCI'
Dicti::;30_CARR!EII
m
� Sa!D4JO_ACJC'l'REV
o� ...
'J!,l S41)4lO_BOO(_AGI
Cld+AII+�)
Op,en,nProj«I
lllill,r,1,1inn
Copy
Ctrl•C
,C
Odeh!
D,ltt•
£::.
GttWlm•·u.odl.ill!. ..
Act...,ti,;n Leg
@ Aet:M! Annot&tion.s
1',!..,,0rttOefimtion
Dupli<•te. ..
llitwl
$h1rclinli;. ..
1
_...._
,,
Sold430_Carrlc,r
• Cffl1cl
III
. ....
III
ClrfNJ:'JII
cvrroooe,
_
n
"'""'"
...
Figure 32: Graphical Editor for CDS Views
The Graphical Editor for CDS Views is another useful tool that supports you in analyzing
complicated DDL Sources. It not only shows how the given CDS View depends on other
© Copyright. All rights reserved.
29
Unit 1: Introduction
repository objects, it also provides a graphical representation of the projection list and
displays details about aggregations, filters, etc.
Open a given DDL Source in the Graphical Editor as follows:
1. Right-click DDL Source. (Either in the editor window or in the Project Explorer).
2. Choose Open With→ Graphical Editor.
The Graphical Editor opens in a new tab in the editor window.
Dependency Analyzer
OEVS40430 (p,1utty IQ<lded)
" it
0EV541)430J)EMO
C�llott�;<,i,:
D1tit Odinltiom
(!J s,l[143(1.,AGENC'l'_Y.IITl-l_ll!MNU! O.ma Tn,.�IAg•nty .. �n Toi..,rR..,.nu•
(iJ s.lDA30.BOOKING_AND.)IG[NCY
• S.:D43IOCAMIE!I:
Dictieo,ny
o.-e:-i.--
-
(B Now o.i� 0. ,nition
Vi�
llupli<�te. ..
�$11)43(1.}l,GC:Vl!EV
� S-![143(1_800)(.AOC'
O?m
0 ..,,nP<Q- I
'111 s.lDA.W_CAR!I
o..tl!'Prarii!W
O?mWith
A<t;...;,1ion Log
Copy
@
AflrJ� Anr.o ..ation.s
lloli!b!
-
Annot.tion Propo�otion
,
(!J S.:IMJO.CIJ,TOMER "" Sh�•� !int<. ..
t.'I
(A.l"I...IIM t""r1ei"nul!':!Q,
(l) 11:QGJ S.:D430_C.A
. ER
Jo IKQGI S40l30.Cil.!tRll:R ll
SQL Depemlem:y Tree
SQL Relation
Objro l)'P•
Entify·N,m•·
lnt,ba« ObjKI
Figure 33: Dependency Analyzer
For more sophisticated DDL Sources, it can be quite difficult to find the actual source of the
data. This becomes particularly true if a CDS View reads from several other objects and if
these other objects are not just database tables but CDS Views that again depend on other
objects.
The Dependency Analyzer offers a simplified view by focusing on the dependancy tree and
disregarding the rest.
Open a given DDL Source in the Dependency Analyzer as follows:
1. Right-click DDL Source. (Either in the editor window or in the Project Explorer.)
2. Choose Open With→ Dependency Analyzer.
The Dependency Analyzer opens in a new tab in the editor window.
30
© Copyright. All rights reserved.
Lesson: Analyzing and Using A CDS View
Data Preview
'It
v
DEV'.11)4:JO p.,rtf,load...tJ
" $ DEvS-ID430_0lMO
Doti Oolin�iorn,
@ 54D430.).GEJNC'(l'l'lTH..JREVENLIE Demo: T,a....r A;tnr:y » th Taal�"""'
• S4D430_900�1111G_ANO_AG!;NC,
I
54D430 (.e.JIRIER �
(D N!WD•t• O..tinition
Oicii,i>ntty
o.p1ic-itt. ..
Vi�
111', SilD430_AGCYlt!'
"jl\ 54D430_800K,,A
QpSI
�pminProjc<t
OpSIWith
CoP'.I'
llttm Amnot,lions
C!lete
Annotation Prop1gation
,.
llopend�An,1per
D
FS
Gr•phi><,I Edhor
Figure 34: Data Preview for CDS Views (1)
The Data Preview tool allows you to analyze the data returned by a CDS View without the need
to implement a SELECT statement yourself. In that sense, it is very similar to the Data
Browser tool of the classical ABAP workbench (transaction code SE16).
Open the Data Preview for a given DDL Source as follows:
1. Right-click DDL Source. (Either in the editor window or in the Project Explorer.)
2. Choose Open With→ Data Preview.
The Data Preview opens in a new tab in the editor window.
• IKQGJ So1D430_CARR.IER
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us£I
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EUR
AC
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AF
IJ.hfrillKC
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Gl!P
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BA
co
B,;wh A;rw,,..
Co•tinlt'LtJIAi, ...
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hlipo,lfwhdpO//whllp://w._
htlp,lfw.�
hdpO//Whttpo//W,-
�ttp:llw...
USE)
11f!,
Jllton
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S11l'!�C)_CAAIIH:'.R-CARII.ID,
34 ll4 30_CARRI E:EI-CARHlliO!E1
S41l451)_CAJl.1Uc:ll;<UP;RCOOE,
S4 lli 3Cl_CARRI !:R�URL
FIIOH
I"'
34 ll4 30_CARRH'.R
I
x
Nuon ,,.. of Entri�
N\Irnl!or oi �lies thM m .. 1 lh• soloction <rimi.., 13
OK
Figure 35: Data Preview for CDS Views (2)
The Data Preview lists the first n entries of the specified view or table. N is set to 100 by
default but can you can increase or decrease this value manually (setting Max.Rows).
© Copyright. All rights reserved.
31
Unit 1: Introduction
The toolbar on the Raw Data tab offers additional functions:
Add filter
Opens a dialog to enter selection criteria
Number of Entries
Displays the total number of rows in the table/view that match the selection criteria
SQL Console
Opens a new editor window with a SELECT statement for this view/table. You can edit
this statement, execute it, and display the result to run a more sophisticated ad-hoc
analysis of the data.
A New Syntax for Open SQL
Classical Syntax (Before NW 7 .40 SP05)
SELECT carrid connid fl.date SUM( payment.sum I currency
FROM sflight
INTO TABLE gt_flights
WHERE fldate > sy-datum
GROUP BY carrid co.nnid f'ldate currency
ORDER BY carrid connid.
New Syntax Rules in NW 7.40
SELE.C'T c:arrid, c:onnid, fl.date, SUM( paymentsum ) , c:u.rrenc:y
FROM sflight
INTO TABLE @gt_flights
WHERE fldate > @sy-datum
Variables must
be escaped with
the @symbol
GROUP BY carrid, connid, fl.date, cu.rrency
ORDER BY carrid, connid.
Column lists are
now commaseparated
I
Figure 36: New Open SQL Syntax in NW 7.40
As off AS ABAP 7.40 SP05, ABAP Open SQL offers a large variety of new features. In order to
make this possible, it was necessary to re-design the Syntax of Open SQL. The new Syntax
Rules as off NW 7.40 are as follows:
●
●
Comma-separated column lists — to allow for sophisticated expressions
Mandatory escape character @ for ABAP data objects — to ensure a clear distinction
between database objects (tables and table columns) and objects of the ABAP program
(variables and constants).
Regarding the usage of old syntax and new syntax, the following rules apply:
●
●
●
32
If an SQL statement uses the new syntax, it has to use it consequently.
An SQL statement may use the old syntax as long as it contains only features that were
already available before NW 7.40 SP05 (compatibility mode).
As soon as an SQL statement contains a single feature that was introduced in or after NW
7.40 SP05, it has to follow the new syntax rules (strict mode).
© Copyright. All rights reserved.
Lesson: Analyzing and Using A CDS View
I»
Note:
CDS Views were introduced in NW 7.40 SP05. The new syntax is mandatory when
using a CDS View in a SELECT statement.
Classical Sequence of Clauses
SELECT carrid connid f1date SUM( paymentsum) eurrency
FROM sflight
INTO TABL,E gt_flights
WHERE fldate > sy-datwn
GROUP BY carrid connid f1date currency
ORDER. SY carrid connid.
Nlew Syntax Rules in NIW 7. 50
SELECT
FROM clause
before field list
Keyword FIELDS
to introduce
Field list
FROM sfligh t
FIEWS carrid, connid, fldate, SUN( paymentsum ), currency
WHERE fldate > @sy-datum
GROUP a:y carrid, connid, fldate, c.urrency
ORDER iB.'f carrid, connid
INTO at the
IN'FO TABLE @gt_flights.
very end
(> NW 7.40)
Figure 37: New Open SQL Syntax in NW 7.50
AS ABAP 7.50 brought more new features to Open SQL and, along with those, additional
changes to the syntax. Most important, the sequence of clauses was changed as follows:
●
●
Field list after FROM clause, introduced by new key word FIELDS — to allow for autocompletion when editing the field list
INTO clause at the very end of the statement — to support the UNION of several SELECT
statements with one INTO clause
Regarding the usage of this new syntax, the following rules apply:
●
●
An SQL statement may use the old sequence of clauses as long as it contains only features
that were available before NW 7.50.
As soon as an SQL statement contains a single feature that was introduced in or after NW
7.50, it has to use the new sequence of clauses (strict mode for NW 7.50).
Note:
Some features of CDS were first introduced in NW 7.50. If the definition of a CDS
View contains such a feature, any SELECT statement reading from this CDS View
has to use the new sequence of clauses.
© Copyright. All rights reserved.
33
Unit 1: Introduction
One DDL Source – Two Objects to Read from
DDL Source
SQLView
SELECT ...
FROM <SQL View name>
CDS View Entity
OR
?
SELECT ....
FROM <CDS View name>
Use of SOL View is ...
Use of CDS View is ...
• Not recomrnendedl
• Recommended!
•
Supported with classical
and new syntax
• Only possible with
new syntax
•
Obsolete since NW 7 .50
• Not fully supported
before Rel. NW 7.50
(e.g.in joins with DB tables)
Figure 38: One DDL Source – Two Objects to Read From
To use CDS in ABAP Open SQL, you can read either from the SQL View or from the CDS View.
This might be a bit surprising because only the SQL View exists physically on the database.
But if you read from the CDS View, the database interface will replace the name of the CDS
View with the name of the corresponding SQL View when translating your Open SQL
statement into a native SQL statement. This is the recommended way to access CDS views in
ABAP.
Alternatively, it is also possible to read from the SQL View directly. This was never
recommended and became obsolete with NW 7.50.
Note:
In systems with release NW 7.40, CDS Views are not yet fully supported in Open
SQL. Reading from the SQL View is then needed as a workaround. One example is
the join of a CDS View with a database table. This is possible in NW 7.50 or higher.
The workaround in NW 7.40 is a join of the corresponding SQL View with the
database table.
34
© Copyright. All rights reserved.
Unit 1
Exercise 2
Analyze a CDS View and Use It in Open SQL
Business Example
Template:
S4D430_INTRO_S1 (Executable Program)
Solution:
S4D430_INTRO_S2 (Executable Program)
Search for a DDL SQL View and Navigate to the Definition
In ABAP Development Tools, search for SQL View S4D430_CUSTREV. Open the SQL View.
Then navigate to the corresponding data definition (DDL Source).
1. In ABAP Development Tools, start a search for the ABAP repository object with name
S4D430_CUSTREV.
2. Open the corresponding package in the project explorer on the left.
3. Open the corresponding data definition (DDL Source).
Hint:
Use the context menu in the project explorer to navigate to the view’s
definition.
What is the name of the DDL Source?
What is the name of the CDS View?
Analyze the CDS View with Different ADT Tools
1. Open the DDL Source with the Dependency Analyzer.
© Copyright. All rights reserved.
35
Unit 1: Introduction
Which database tables do the data come from?
2. Open the DDL Source in the Graphical Editor.
3. Open the Active Annotations view for the DDL Source.
Open Data Preview for the CDS View
1. Use the Data Preview tool to display the raw data for this view.
2. Set a filter to display only flight customers located in Germany.
Implement a SELECT Statement That Reads Data from the SQL View
Use the SQL View as ABAP data type and as source for a SELECT statement.
Note:
The use of SQL Views in ABAP programs is obsolete as of AS ABAP 7.50. We do it
here only for didactical reasons. SAP recommends to access the CDS Views only
(see next part of this exercise).
1. Create a copy of your solution of the previous exercise in your package (suggested name:
Z##_OPEN_SQL, where ## is your group number). Alternatively, you can copy program
S4D430_INTRO_S1.
2. Change the definition of local data type ty_t_customers. Replace line type SCUSTOM with
SQL View S4D430_CUSTREV.
3. Change the SELECT statement. In the FROM clause, replace transparent table SCUSTOM
with SQL View S4D430_CUSTREV.
4. Activate and test your program.
Implement a SELECT Statement That Reads Data From the CDS View
Use the CDS Viewas
View ABAP data type and as source for a SELECT statement.
1. Change the definition of local data type ty_t_customers again. This time, replace SQL View
name S4D430_CUSTREV with the corresponding CDS View
S4D430_Customer_With_Revenue.
2. Check for possible syntax errors.
Why are SQL View and CDS View not compatible?
3. Adjust the SELECT statement to make it read data from the CDS View.
36
© Copyright. All rights reserved.
Lesson: Analyzing and Using A CDS View
Why do you get syntax errors that requests a “@” before data object gt_customers?
4. Adjust the SELECT statement according to the new syntax rules as of Release 7.40: Add
colons between column names and place character “@” in front of all ABAP data objects.
5. Activate and test your program.
© Copyright. All rights reserved.
37
Unit 1
Solution 2
Analyze a CDS View and Use It in Open SQL
Business Example
Template:
S4D430_INTRO_S1 (Executable Program)
Solution:
S4D430_INTRO_S2 (Executable Program)
Search for a DDL SQL View and Navigate to the Definition
In ABAP Development Tools, search for SQL View S4D430_CUSTREV. Open the SQL View.
Then navigate to the corresponding data definition (DDL Source).
1. In ABAP Development Tools, start a search for the ABAP repository object with name
S4D430_CUSTREV.
a) Choose Search from the menu or hit keys Ctrl+H.
b) On the ABAP Object Search tab, enter S4D430_CUSTREV in field Object name and
choose Search.
2. Open the corresponding package in the project explorer on the left.
a) On the Search tab below the editor window, double-click the found repository object.
This will open the SQL View in the ABAP Dictionary tool and will expand package
DEVS4D430_EXERCISE in the Project Exporer.
3. Open the corresponding data definition (DDL Source).
Hint:
Use the context menu in the project explorer to navigate to the view’s
definition.
a) In the Project Explorer, right-click the SQL View and choose Open With→ Definition.
What is the name of the DDL Source?
S40430_CUSTOMER_WITH REVENUE (all upper case)
What is the name of the CDS View?
S4d430 Customer With Revenue (mixture of upper and lower case)
Analyze the CDS View with Different ADT Tools
38
© Copyright. All rights reserved.
Lesson: Analyzing and Using A CDS View
1. Open the DDL Source with the Dependency Analyzer.
a) Right-click anywhere in the source code of the DDL Source and choose Open
With→ Dependency Analyzer.
Which database tables do the data come from?
SCUSTOM and SBOOK
2. Open the DDL Source in the Graphical Editor.
a) Right-click anywhere in the source code of the DDL Source and choose Open
With→ Graphical Editor.
3. Open the Active Annotations view for the DDL Source.
a) Right-click anywhere in the source code of the DDL Source and choose Open
With→ Active Annotations.
Open Data Preview for the CDS View
1. Use the Data Preview tool to display the raw data for this view.
a) Right-click anywhere in the source code of the DDL Source and choose Open
With→ Data Preview.
2. Set a filter to display only flight customers located in Germany.
a) From the toolbar within Data Preview, choose Add Filter.
b) From the dropdow list, choose field Country
c) Enter filter value DE and choose Enter.
Implement a SELECT Statement That Reads Data from the SQL View
Use the SQL View as ABAP data type and as source for a SELECT statement.
Note:
The use of SQL Views in ABAP programs is obsolete as of AS ABAP 7.50. We do it
here only for didactical reasons. SAP recommends to access the CDS Views only
(see next part of this exercise).
1. Create a copy of your solution of the previous exercise in your package (suggested name:
Z##_OPEN_SQL, where ## is your group number). Alternatively, you can copy program
S4D430_INTRO_S1.
a) See the corresponding step in the previous exercise.
2. Change the definition of local data type ty_t_customers. Replace line type SCUSTOM with
SQL ViewS4D430_CUSTREV.
View
a) See source code extract from the model solution.
3. Change the SELECT statement. In the FROM clause, replace transparent table SCUSTOM
with SQL View S4D430_CUSTREV.
a) See source code extract from the model solution.
4. Activate and test your program.
a) See the corresponding step in the previous exercise.
© Copyright. All rights reserved.
39
Unit 1: Introduction
Implement a SELECT Statement That Reads Data From the CDS View
Use the CDS Viewas
View ABAP data type and as source for a SELECT statement.
1. Change the definition of local data type ty_t_customers again. This time, replace SQL View
name S4D430_CUSTREV with the corresponding CDS View
S4D430_Customer_With_Revenue.
a) See source code extract from the model solution.
2. Check for possible syntax errors.
a) Open the Problems tab on the tabstrip below the editor.
Why are SQL View and CDS View not compatible?
The SQL View has a client field (MANDT) which is missing from the CDS View.
3. Adjust the SELECT statement to make it read data from the CDS View.
a) See source code extract from the model solution.
Why do you get syntax errors that requests a “@” before data object gt_customers?
The new syntax for Open SQL is mandatory when you use a CDS View in the FROM clause.
4. Adjust the SELECT statement according to the new syntax rules as of Release 7.40: Add
colons between column names and place character “@” in front of all ABAP data objects.
a) See source code extract from the model solution.
5. Activate and test your program.
a) Perform this step as you did in the previous exercise.
Program S4D430_INTRO_S2
REPORT s4d430_intro_s2.
*TYPES ty_t_customers TYPE STANDARD TABLE OF scustom
* WITH NON-UNIQUE KEY id.
*TYPES ty_t_customers TYPE STANDARD TABLE OF S4D430_CUSTREV
* WITH NON-UNIQUE KEY id.
TYPES ty_t_customers TYPE STANDARD TABLE OF
s4d430_customer_with_revenue
WITH NON-UNIQUE KEY id.
DATA gt_customers TYPE ty_t_customers.
* ALV Processing
DATA go_salv TYPE REF TO cl_salv_table.
DATA gx_excp TYPE REF TO cx_salv_error.
* Selection Screen
PARAMETERS pa_city TYPE s_city DEFAULT 'New York' LOWER CASE.
START-OF-SELECTION.
40
© Copyright. All rights reserved.
Lesson: Analyzing and Using A CDS View
* Data Retrieval
****************************************************************
*
*
*
*
SELECT * FROM scustom
INTO TABLE gt_customers
WHERE city = pa_city
order by city name.
* Option 1: Read from the SQL View (Obsolete as off Rel. 7.50)
***************************************************************
* SELECT * FROM s4d430_custrev
* INTO TABLE gt_customers
* WHERE city = pa_city
* order by city name.
* Option 2: Read from the CDS View (Recommended)
****************************************************************
SELECT * FROM s4d430_customer_with_revenue
INTO TABLE @gt_customers
WHERE city = @pa_city
ORDER BY city, name.
* output
****************************************************************
TRY.
cl_salv_table=>factory(
IMPORTING
r_salv_table = go_salv
CHANGING
t_table = gt_customers
).
go_salv->display( ).
CATCH cx_salv_error INTO gx_excp. "
MESSAGE gx_excp TYPE 'I'.
ENDTRY.
© Copyright. All rights reserved.
41
Unit 1: Introduction
LESSON SUMMARY
You should now be able to:
42
●
Read a Data Definition
●
Use CDS-related Tools in ADT
●
Use Open SQL to Read From a CDS View
© Copyright. All rights reserved.
UNIT 2
Basic SQL Features in CDS
Views
Lesson 1
Define a Simple CDS View
Exercise 3: Define a Simple CDS View
44
51
Lesson 2
Creating a CDS View with Inner Join, Projection, and Selection
Exercise 4: Define a CDS View That Reflects a Database View
56
61
Lesson 3
Using ABAP Annotations in CDS Views
Exercise 5: Use Annotations in DDL Sources
67
73
UNIT OBJECTIVES
●
Create a DDL Source
●
Understand the DDL Syntax Rules
●
Define a CDS View That Reflects a Database View
●
Use ABAP Annotations in CDS Views
●
Work with Translatable Texts in CDS
© Copyright. All rights reserved.
43
Unit 2
Lesson 1
Define a Simple CDS View
LESSON OBJECTIVES
After completing this lesson, you will be able to:
●
Create a DDL Source
●
Understand the DDL Syntax Rules
Create a new DDL Source
Right-Click the
Project
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flatort from �.:,,;ii Hi>t<>ry•.
O:thu•.
CUl+N
Figure 39: Create New DDL Source (1)
To create a new DDL Source, proceed as follows:
1. Right-click on your project in the Project Explorer.
2. Choose New→ ABAP Repository Object …
44
© Copyright. All rights reserved.
Lesson: Define a Simple CDS View
r"'
Now ABAP R.op<><�'OJ)' Objttt
D
x
1
ASAP· R�jHi$ito;y Object
c, ..tt ,n ASAP 11:tpof ory Objed
froject:
! KQG.800.m• nut.on
d,1�del
Cl
Oato Oefinilio,r,
Crc•I• • D,11 Ddiniti,m
E,ojoct: •
----------------------t
Ptcbge; ·
"'-----------'
'
Add 10 1¥••1• pa.,k.og.,
ll_6Cription:•
--------------------1
rm::
..,
Oliginal�nguago: ....
Figure 40: Create New DDL Source (2)
3. From the list, choose Core Data Services→ Data Definitions
[o
Hint:
You can use the input field below Project to type a search term, e.g. "data".
4. Choose Next.
5. Enter the name of an (existing) package, and a name and description for the new DDL
Source.
© Copyright. All rights reserved.
45
Unit 2: Basic SQL Features in CDS Views
OEVS40!.0 (p1rtt,, l�d«ll
" $ DEVS4D430.DEMO
.c
WD
IM
1
S
i
x
(J
Ntw Dal• Ddinition
Oll!a DBfinition
I
CrieateaiDi!lllDefini1ion
Right-Click
Data Definitions
under package
Br-e...
t,me:a•
jlH<riplion:•
Orfqin' 1/jngutgc: L.E_II
___.
Figure 41: Shortcut (If Package Already Contains a DDL Source)
If your package already contains a DDL Source, you can use the following shortcut:
1. In the Project Explorer, expand subnode Core Data Services→ Data Definitions of the
favorite package.
2. Right-click Data Definitions and choose New Data Definition.
DDL Source Templates
Ill
o
x
Templi!.te ...
klt<t ene of the .w;il;blc lempl,ld.
ll'U:Vit'w'
(JjD•lin•ViowYoithJoin
m
Deline View will, A$...,<ililrM
Dd'ioe View ..ill, P•rjl!'l<l,n
BJEximdVi""
(!I Define Tal>I• Function wilh Pa,•metm
iAba,i:,C t.o.lcv.:,<1lVi.,,..N=";
"S(o<1l """"' c.�ef'
@Al>o.l'Co.u,ioo. ecrepu .... ec,tpo.re!'1l;er: ;'.-ue
8,Acee,:s:sCocti'C-rol. auit.horl.%.aoel.onChect::
@,E::LdUs�rTe:x.ic.. h.bl!l:
ICHE.CK
• S �ddl_s:eiu:rce:_dll!:sc�1.p:t.1cn) •
<hot:1.m, vi."" Sl<lcll ,.:. .. .-o:., nm.i: "cl1t.a1>hl
Hc1:1r,,orJ
-
-
-
4:,;
-l!ele,;:, :...,,. S[<l11n. oc,i..-o:" nL"<"I
-
-
I
c.n�,I
Figure 42: DDL Source Templates During DDL Source Creation
When you create a new DDL, you can create a blank editor page. Alternatively, you can use
one of several available templates as a starting point.
46
© Copyright. All rights reserved.
Lesson: Define a Simple CDS View
Usually, a respective dialog appears after you assigned the new DDL Source to your ABAP
workbench request. But you can always return to the template selection later in the editing
process.
"IK
i.AballCa"GailaQI. aql V.1.ewHame.
�
9Accc.o.oCc,nercl 11ue:,or1:t4Ue>nCbcck
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1
Deom:i. Tz-avel AQ�nc:y'
tlne; V1ev S.1Jl'.M30_.AQ�nc:,i· n.a Sil!i1.ect :rrcs C1a&a_;5.ourcl!_naJDI!:' f
8LndU.sezTex,:. .la.be1 •
s
6
07
' aql v .iew name•
,eAb<lpCa ,•1011. """"'l.lo:r comp,oro:P'11,cr- true
-
-
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DataOefiilitiOII
" 'll Dota Oelinition [croaoon)
Bi delineT1bl�un�ionl'l�hli'1r1met�
t dd"m!Viow
L
m def"meVi��(>(iltion
D..tinoView
�imt Vitw wi�h A:$.$O�i:ttion1
i,i dd"m!ViowWithlcin
D..tino \li.wwith loir,
Bi define'l"ow
€J•••tondVt...,
(>�;·� V.ow w�h p
E>und\C,-,
ol'IP�l"'elffl
fJMe.«f$
Figure 43: DDL Source Templates During Editing
To choose a template later, go to the Templates tab in the tabstrip below the editor window.
I»
Note:
You may define your own templates in the editor preferences. Go to
Window→ Preferences and search for “Data Definition Templates”.
© Copyright. All rights reserved.
47
Unit 2: Basic SQL Features in CDS Views
Syntax Rules
• Keywords:
All uppercase, alll lowercase, or lowercase with uppercase iniitiial lette.r.
No mixed uppercase and lowercase
Allowed: SELECT, select, Select Not alllowed: Select, seleCT.
• Names:
Not case-sensitive. Max. 30 characters.
Literals:
Numeric literals always in full, with decimal point if necessary.
Allowed: 1, 2.0, or 0.5. Not allowed: .5, 1,3
Character !literals enclosed in single quotations marks I'),
'LH', '00001'
Comments:
Explicit end: enclosed by /" and --1
Rest of line: two forward slashes (II)
• Separators:
Statements can be closed usiing a semicolon (;). This is optional.
• Prntected Words:
Certain keywords cannot be used as self-defined names
J
Figure 44: General DDL Syntax Rules
The general syntax rules inside DDL Sources are as follows:
Keywords
Keywords must be all uppercase, all lowercase, or in lowercase with an uppercase initial
letter. Mixed uppercase and lowercase is not allowed.
Names
Names are not case-sensitive. A name can have a maximum of 30 characters.
Literals
Number literals must always be specified in full and a decimal point (.) used as a decimal
separator if necessary. Character literals are enclosed in single quotations marks (')
Comments
Two forward slashes (//) introduce a comment, which continues until the end of the line.
Comments within lines or that span multiple lines are enclosed by the characters /* and
*/.
Separators
Statements can be closed using a semicolon (;). This is optional because, for the
moment, one piece of CDS source code can currently only contain a single statement.
Protected Words
Certain keywords are protected and cannot be used as self-defined names.
48
© Copyright. All rights reserved.
Lesson: Define a Simple CDS View
Standard SOL ( After keyword SELECT )
@AbapCatalog.sqlViewName: '54D430_CARR'
define view S4D430_Carrier as select carrid,
carr-nama,
curr-eeda,
url
from scarr
CDS DDL Style,( After FROM-Clause, enclosed in,,{" and ,.}" )
@AbapCatalog.sqlViewName: 'S4D430_CARR'
define view S4D4:30_:Carrier as
select from scarr
car rid,
carrname.,
cur re ode,
url }
I
Figure 45: Variants for Specifying the Element List
When you define a CDS View, you have two options to specify the element list (that is the field
list in the simplest case):
1. After keyword SELECT, before keyword FROM.
This corresponds to SQL standard syntax.
2. Enclosed in characters "{" and "}", after the FROM clause of the SELECT statement
This is a speciality of to CDS Syntax and allows for improved auto-completion support.
It is recommended to use second, CDS-specific syntax.
Note:
Regarding auto-completion support, the CDS-specific syntax corresponds to
addition FIELDS in Open SQL.
Naming Rules and Recommendations
Regarding the names of DDL Source, CDS Entity, and SQL View, there are some hard rules
enforced by the development tools, and mere recommendations that are intended to increase
clearness and readability.
© Copyright. All rights reserved.
49
Unit 2: Basic SQL Features in CDS Views
DDL Source name:
• Max. 30 Characters
• Unique throughout the system (Customer narnespacel)
Always Upper-Case
CDS View name:
•
•
•
•
•
Max 30 Characters
Unique throughout the system (Customer namespace!)
Unique within AB.AP Dictionary (global ABAP data type)
Not Case-sensitive
Can be different from DDL Source name (not rscommendedl)
SQL View name:
• Max 16 Characters (Standard Diictionary Object)
• Unique throughout the system (Customer narnespacel)
Unique within .ABAP Dictionary (global ABAP data type)
• Not Case-sensitive (will be translated to Upper Case)
Different from CDS View name
J
50
Figure 46: Naming Rules and Recommendations
© Copyright. All rights reserved.
Unit 2
Exercise 3
Define a Simple CDS View
Business Example
Template:
none
Solution:
S4D430_SIMPLE (DDL Source)
Create a new DDL Source
1. In your own Package, create a new DDL Source (suggested name: Z##_SIMPLE, where
## stands for your group number). Choose template defineView to generate the definition
statement and some standard annotations.
2. If the tool did not ask for the template, go to the templates tab on the tabstrip below the
editor and choose the template there.
3. In the respective Annotation, enter a name for the SQL View that is to be generated
(suggested name: Z##SIMPLE).
4. Would it be possible to specify the same name for CDS View and SQL View?
5. What is the maximum length for the name of the SQL View?
Implement the DDL Source
1. In the FROM clause of the SELECT statement, specify database table SBOOK.
2. Edit the field list of the SELECT Statement. Start with the complete key of table SBOOK,
except for the client field. Add the fields for flight class, booking price in foreign currency
(with the corresponding currency key), weight of luggage (with corresponding weight
unit), booking date, travel agency number, counter number and customer number.
Hint:
To enter the field names, make use of the editor’s auto-completion
capabilities!
© Copyright. All rights reserved.
51
Unit 2: Basic SQL Features in CDS Views
Activate the DDL Source and Test the Result
1. Perform a syntax check. Then activate the DDL Source.
2. In the Project Explorer window, refresh the object list for your package and locate the DB
view that has been created.
3. Open the Data Preview for your CDS View.
52
© Copyright. All rights reserved.
Unit 2
Solution 3
Define a Simple CDS View
Business Example
Template:
none
Solution:
S4D430_SIMPLE (DDL Source)
Create a new DDL Source
1. In your own Package, create a new DDL Source (suggested name: Z##_SIMPLE, where
## stands for your group number). Choose template defineView to generate the definition
statement and some standard annotations.
a) In the ABAP perspective of Eclipse, right-click on your project and choose New
→ Other ABAP Repository Object.
b) On the next window, choose Core Data Services→
Data Definition.
c) Enter the name of your package, a name, and a short description for the new object,
and choose Next.
d) If the tool asks for a template, select defineView and choose Next.
e) Assign the object to your transport request and choose Finish.
2. If the tool did not ask for the template, go to the templates tab on the tabstrip below the
editor and choose the template there.
a) Go to tab templates on the tabstrip below the editor.
b) Select template defineView.
3. In the respective Annotation, enter a name for the SQL View that is to be generated
(suggested name: Z##SIMPLE).
a) See source code extract from the model solution.
4. Would it be possible to specify the same name for CDS View and SQL View?
No. They need to be distinguishable when they are used. e.g., in ABAP coding.
5. What is the maximum length for the name of the SQL View?
16 Characters
Implement the DDL Source
© Copyright. All rights reserved.
53
Unit 2: Basic SQL Features in CDS Views
1. In the FROM clause of the SELECT statement, specify database table SBOOK.
a) See source code extract from the model solution.
2. Edit the field list of the SELECT Statement. Start with the complete key of table SBOOK,
except for the client field. Add the fields for flight class, booking price in foreign currency
(with the corresponding currency key), weight of luggage (with corresponding weight
unit), booking date, travel agency number, counter number and customer number.
Hint:
To enter the field names, make use of the editor’s auto-completion
capabilities!
a) For auto-completion, press keys Ctrl and Space at the same time.
b) See source code extract from the model solution.
Activate the DDL Source and Test the Result
1. Perform a syntax check. Then activate the DDL Source.
a) Choose Check ABAP Development Object or hit Ctrl + F2.
b) Choose Activate or hit Ctrl + F3.
2. In the Project Explorer window, refresh the object list for your package and locate the DB
view that has been created.
a) Place the cursor on your package.
b) Choose Refresh from the context menu or hit F5.
c) Open subnode Dictionary→ Views.
3. Open the Data Preview for your CDS View.
a) In the Project Explorer, right-click on your DDL Source and choose Open With→ Data
Preview.
DDL Source S4D430_SIMPLE
@AbapCatalog.sqlViewName: 'S4D430_SIMP'
@AbapCatalog.compiler.compareFilter: true
@AccessControl.authorizationCheck: #CHECK
@EndUserText.label: 'Solution: Simple CDS View Definition'
define view S4D430_Simple as select
from sbook
{ carrid,
connid,
fldate,
bookid,
class,
forcuram,
forcurkey,
luggweight,
wunit,
order_date,
agencynum,
counter,
customid
}
54
© Copyright. All rights reserved.
Lesson: Define a Simple CDS View
LESSON SUMMARY
You should now be able to:
●
Create a DDL Source
●
Understand the DDL Syntax Rules
© Copyright. All rights reserved.
55
Unit 2
Lesson 2
Creating a CDS View with Inner Join,
Projection, and Selection
LESSON OBJECTIVES
After completing this lesson, you will be able to:
●
Define a CDS View That Reflects a Database View
Inner Join in DDL Source
define view 540430 Connectionl Jloin a1s select
from
spfli
inner join scarr
on spfli.carrid = scarr.carrid
spfl!.i. car.rid,
spflli.connid,
soarr.carrname,
scarr.currcode,
sp:fli.cityfrom,
spflli.cityto,
airpfrom,
airpto
Use Separator is,,." not,,-"
(SQIL standard, not Open
SQL Syntax)
Table name mandatory
where field name alone is
ambiguous
Figure 47: Inner Join in DDL View Definition
56
© Copyright. All rights reserved.
Lesson: Creating a CDS View with Inner Join, Projection, and Selection
Aliases for Tables and Fields
define view S4D430_Connection2_Alias as select
from
inner join ,.s_c_a_r on
a.carri
_
�..-,-11 1 1C---...--
{
lcarrid,
connid,
carrname,
curr_ code as ,currency,
__
cityfrom,
cityto,
airpfrom,
airpto
Alias for
tabie name
Alias for
element
(mandatory
for certain
expressions)
Figure 48: Aliases for Tables And Fields
In the element list, addition AS defines an alternative element name. The alternative element
name replaces the actual name of the element from the data source data_source. The view
field is created under the alternative element name in the CDS database view. Accordingly,
the alternative element name must comply with the rules for names of view fields of database
views, as well as the general naming rules for names, which means that it must also meet the
naming conventions for component names of structures in ABAP Dictionary and cannot be a
reserved component name. The reserved names that cannot be used are maintained in
database table TRESE.
Alternative element names can be used in the current CDS view to grant unique names for
identically named elements from different entities of the data source. When the current CDS
view is accessed, the alternative element names must be used instead of the actual name.
Note:
Alternative element names cannot be used within the CDS view, with one
exception: alternative element names can be specified directly or after $projection
in the ON condition of anassociation.
© Copyright. All rights reserved.
57
Unit 2: Basic SQL Features in CDS Views
Key Definition
l@AbapCatalog.preserveKey: true
define view S4.D43.0_Connect101n3_Keys as select
Define these
elements as
key elements
from
spf.!i as c
inner join scarr as a
on c. carrid = a. carrid
{
{ke;l c _. car rid,
�c.connid,
a.carrname,
Create database
objcect with the
specified key
Need to be start
elements of list
(without gaps)
a. currcod.e as currency,
c.cityfrom,
c.cityto,
airpfrom,
airpto
]
Figure 49: Key Definition
KEY is used to define the current element as a key element of the current CDS entity. Any
elements of a SELECT list can be defined as key elements that are placed without gaps at the
start of the list.
The key elements of the CDS entity are evaluated as follows if they are used as a data source
of a SELECT statement in Open SQL:
●
●
By the addition ORDER BY PRIMARY KEY. In this case, the key elements must be defined
at the start of the SELECT list without any gaps.
In implicit access control.
By default, the key elements of the CDS entity are used to document the semantics of the
data model. The addition KEY is then ignored when the CDS view is activated and when other
accesses are performed in program executions.
The default setting can be overridden using the view annotation AbapCatalog.preserveKey:
●
●
58
If the value true is specified for this annotation, the key elements defined using KEY are
also used as keys of the CDS database view.
If this annotation is not specified or specified with the value false, the key elements defined
using KEY are ignored by the key of the CDS database view. Like in classic views, the key
fields of the database view are derived implicitly from the key fields of the basis tables and
the join conditions. If this is not possible, all fields of the database view are key fields.
© Copyright. All rights reserved.
Lesson: Creating a CDS View with Inner Join, Projection, and Selection
Selections
de-fine view S4:0430_Connection4_Selection as select
from
spfli as c
inner join scarr as a
on c.carrid
a.carrid
key c.carri.d,
key c.conni.d,
a.carrname,
a.currcod.e as currency,
c.cityfrom,
Add WHERE
clause to define
a pre-selecti:on
c.cityto,
ai.rpfrom,
ai.rpto
lwhere c. f1type <> 'X'
! I/exclude
charter f1ights
Figure 50: Selections
Addition WHERE defines a condition for the results set of a CDS view. When the CDS view is
accessed, the results set contains only the data from the data source data_source that meets
the condition cond_expr specified after WHERE.
Note:
The fields evaluated in the condition do not need to be defined as elements of the CDS view in
the SELECT list.
© Copyright. All rights reserved.
59
Unit 2: Basic SQL Features in CDS Views
60
© Copyright. All rights reserved.
Unit 2
Exercise 4
Define a CDS View That Reflects a Database
View
Business Example
Template:
S4D430_SIMPLE (DDL Source)
Solution:
S4D430_JOIN_AND_SELECTION (DDL Source)
Create a new DDL Source
1. In your own Package, create a new DDL Source (suggested name:
Z##_JOIN_AND_SELECTION, where ## stands for your group number). Choose template
defineViewWithJoin to generate the definition statement and some standard annotations.
2. In the new DDL Source, provide a suitable name for the DB View (suggested name:
Z##JOIN).
Implement an inner join of tables SBOOK and SCUSTOM
1. In the definition of the CDS View, implement an inner join of tables SBOOK and SCUSTOM.
Refer to the foreign key relations of table SBOOK to find the appropriate fields for the join
condition. Make sure you specify aliases for the two tables.
2. Open your DDL Source Z##_SIMPLE (or the corresponding model solution
S4D430_SIMPLE) and copy the entire field list to your new DDL Source. Optionally, add
the alias for table SBOOK in front of the field names.
3. At the end of the list, add fields for name and address of the customer (Name, Street,
Postcode, City, Country) .
Hint:
Make use of the editor’s auto-completion capabilities to enter the field
names.
Specify the key and provide aliases for some fields
1. Use prefix key to make sure all key fields of table SBOOK are also key fields of your view.
2. Provide an alias for fields FORCURRAM and FORCURRKEY (suggested alias names:
AMOUNT and CURRENCY).
Make sure that cancelled bookings are excluded from this view
© Copyright. All rights reserved.
61
Unit 2: Basic SQL Features in CDS Views
1. Add a WHERE clause to read only bookings that are not cancelled.
Activate and Test
1. Activate the DDL Source.
2. Open the Data Preview for the CDS View and ensure that the displayed data is correct.
62
© Copyright. All rights reserved.
Unit 2
Solution 4
Define a CDS View That Reflects a Database
View
Business Example
Template:
S4D430_SIMPLE (DDL Source)
Solution:
S4D430_JOIN_AND_SELECTION (DDL Source)
Create a new DDL Source
1. In your own Package, create a new DDL Source (suggested name:
Z##_JOIN_AND_SELECTION, where ## stands for your group number). Choose template
defineViewWithJoin to generate the definition statement and some standard annotations.
a) See the corresponding step in the previous exercise.
2. In the new DDL Source, provide a suitable name for the DB View (suggested name:
Z##JOIN).
a) See source code extract from the model solution.
Implement an inner join of tables SBOOK and SCUSTOM
1. In the definition of the CDS View, implement an inner join of tables SBOOK and SCUSTOM.
Refer to the foreign key relations of table SBOOK to find the appropriate fields for the join
condition. Make sure you specify aliases for the two tables.
a) See source code extract from the model solution.
2. Open your DDL Source Z##_SIMPLE (or the corresponding model solution
S4D430_SIMPLE) and copy the entire field list to your new DDL Source. Optionally, add
the alias for table SBOOK in front of the field names.
a) Open the DDL Source in the editor window by double-clicking on it.
b) Select the entire field list.
c) Hit Ctrl + C to copy the source code to the clipboard.
d) Open the new DDL Source in the editor window.
e) Place the cursor between character “{” and “}” and hit Ctrl + V.
f) See source code extract from the model solution.
3. At the end of the list, add fields for name and address of the customer (Name, Street,
Postcode, City, Country) .
© Copyright. All rights reserved.
63
Unit 2: Basic SQL Features in CDS Views
Hint:
Make use of the editor’s auto-completion capabilities to enter the field
names.
a) See source code extract from the model solution. For the use of auto-completion, see
the corresponding step in the previous exercise.
Specify the key and provide aliases for some fields
1. Use prefix key to make sure all key fields of table SBOOK are also key fields of your view.
a) See source code extract from the model solution.
2. Provide an alias for fields FORCURRAM and FORCURRKEY (suggested alias names:
AMOUNT and CURRENCY).
a) See source code extract from the model solution.
Make sure that cancelled bookings are excluded from this view
1. Add a WHERE clause to read only bookings that are not cancelled.
a) See source code extract from the model solution.
Activate and Test
1. Activate the DDL Source.
a) See the corresponding step in the previous exercise.
2. Open the Data Preview for the CDS View and ensure that the displayed data is correct.
a) See the corresponding step in the previous exercise.
DDL Source S4D430_JOIN_AND_SELECTION
@AbapCatalog.sqlViewName: 'S4D430_JOIN'
@AbapCatalog.compiler.compareFilter: true
@AccessControl.authorizationCheck: #CHECK
@EndUserText.label: 'Solution: Inner Join and Selection'
define view S4D430_Join_And_Selection as select
from sbook as b inner join scustom as c
on b.customid = c.id
{ key b.carrid,
key b.connid,
key b.fldate,
key b.bookid,
b.class,
b.forcuram as amount,
b.forcurkey as currency,
b.luggweight,
b.wunit,
b.order_date,
b.agencynum,
b.counter,
b.customid,
c.name,
c.street,
c.postcode,
c.city,
c.country
}
64
© Copyright. All rights reserved.
Lesson: Creating a CDS View with Inner Join, Projection, and Selection
where cancelled <> 'X'
© Copyright. All rights reserved.
65
Unit 2: Basic SQL Features in CDS Views
LESSON SUMMARY
You should now be able to:
●
66
Define a CDS View That Reflects a Database View
© Copyright. All rights reserved.
Unit 2
Lesson 3
Using ABAP Annotations in CDS Views
LESSON OBJECTIVES
After completing this lesson, you will be able to:
●
Use ABAP Annotations in CDS Views
●
Work with Translatable Texts in CDS
ABAP Annotations for Views
I
View Annotations
@Aba Catalog.sqlViewName
@ClientDependent
@EndUserText.label
Element An notations
@Semantics.unitOfMeasure
@EndUserText.label
Parameter Annotations ..
@Environment.systemField
@EndUserText.label
Extension Annotations ..
@AbapCatalog.sg1ViewAppend.Name
Function Annotations ..
@ClientDependent
@EndUserText.label
FrameWOni·5pet: ific
(Evaluated by Framework
like OData. VDM, UI,
Analytics .. ,.) ""'
* See details the respective lessons
See the short outlook on those in the last unit
Figure 51: Classification of SAP Annotations
Dependent on the Evaluation, we distinguish two groups of annotations: ABAP Annotations
and Framework-specific annotations.
ABAP annotations
ABAP annotations define technical and semantic attributes of a CDS object. They are
usually evaluated for every CDS object when activated by the ABAP runtime
environment. ABAP annotations can modify the behavior of Open SQL statements that
access a CDS entity. One important example is how the client dependency of a CDS
entity is defined using the associated ABAP annotation.
FrameworkFramework-specific annotations
In most cases, the framework-specific annotations must be evaluated by the frameworks
of the corresponding software components using a suitable API and are not relevant for
© Copyright. All rights reserved.
67
Unit 2: Basic SQL Features in CDS Views
activations and the ABAP runtime environment. Here, the names and values of these
framework-specific annotations must follow the rules of the relevant framework. For SAP
components, these can be taken from the tables of the Framework-Specific Annotations
document.
Dependent on the Scope, we distinguish 5 groups of annotations:
View Annotations
Annotations for a CDS view. Placed in front of the DEFINE VIEW statement.
Element annotations
Annotations for an element of the SELECT list of a CDS view. Placed in front of or after
the element.
Parameter annotations
Annotations for a parameter of a CDS view. Placed In front of or after the parameter.
Extension annotations
Annotations for a CDS view extension. Placed in front of the EXTEND VIEW statement.
Function annotations
Annotations for a CDS table function. Placed in front of the DEFINE TABLE FUNCTION
statement.
l@AbapCatalog.sqlViewName:
'S4D430CONN5ANN0'
l@ClientDependent,
true
Swfldh on/off
client handling in
Open SQL
1
@AccessControl.authorizationCheck: #CHECK
@AbapCatalog.compiler.CompareFilter: true
Switch on/off implicit
access control in
Open SOL
l
Control evaluation of
filtered associations
@AbapCatalog.Buffering.type: #GENERIC
@AbapCatalog.Buffering.numberOfKeyFields:
@AbapCatalog.Buffering.status: #ACTIVE
I
Switch on/off
buffering of SQL
View in Open SOL
define view S4d430 Connection5 Annotations
I· ..
-
-
Figure 52: Important ABAP View Annotations
For CDS Views, the following important ABAP annotations exist:
AbapCatalog.sqlViewName
Specifies the name of the CDS database view in the CDS view
ClientDependent
Defines client handling when Open SQL is used to access the CDS view. Is optional and
default value is "true".
AccessControl.authorizationCheck
Defines the implicit access control when Open SQL is used to access the CDS view.
68
© Copyright. All rights reserved.
Lesson: Using ABAP Annotations in CDS Views
AbapCatalog.compiler.compareFilter
Defines the evaluation of filter conditions in path expressions of the CDS view.
AbapCatalog.buffering.<...>
Define the buffering of the CDS view in SAP buffering.
ABAP Annotations for View Elements
Semantics for Amount I Currency Code
�
- ...
@Semantics.amount.currencyCode:'CURRENCY' price,
@Semantics.currencyCode: true
currency,
Before or after
the el:ement
...
Semantics for Quantity I UnitOfMeasure
...
distance @<Semantics.quantity.unitOfMeasure:
@<Semantics.unitOfMeasure: true
dist id
....
l
I
DISTID''
Before or after
the element
Figure 53: Important ABAP Annotations for View Elements
The Semantics annotations are used to define the currency fields and quantity fields of CDS
views and CDS table functions.
Like all element annotations they can be located either before or after the element they refer
to.
[o
Hint:
Compare this to the Currency/Quantity Fields tab that is available when editing
transparent tables or structure types in the ABAP Dictionary tool.
© Copyright. All rights reserved.
69
Unit 2: Basic SQL Features in CDS Views
ABAP Annotations for Translatable Texts
View Annotation
Maximum of
60 Characters
.. .
@EndUserText.label:
'Demo: Simple View Definition'
...
Element Annotations
�
"
-
+
-�
@EndUserText.label: 'Discount'
@EndUserText.quickinfo: 'Customer Specific Discount'
c.discount,
�
"
t
1
Maximum of
60 Characters
I
Before or after
the element
Note:
Element text annotations are required if no text is inherited
from data source (i.e. table definition or other view)
J
Figure 54: ABAP Annotations for Translatable Texts
ABAP annotations starting with EndUserText are used to define translatable semantic texts
for a CDS object.
EndUserText.label is available as view annotation or as element annotation. The value is
limited to a length of 60 characters.
EndUserText .quickinfo is only available as element annotation. The value is stored as a string
and can have arbitrary length.
Translation of Annotations
ln/0.I Saeen: Trilnsl8tion Editor
Transaction
SE63
Other Te:«s
ell
IISl'l J3SP Te""" L4\'0'1t- (C:rnao-clie,,s I
DISi>2 J3SP Te"'-" r..,ou" (CHem,•Speci!icJ
CA1 to,er:!'ace itena (�
r-o"l'l@rtace
T"Ullli;!!I
(FU(;S)
['Dto!-:r"ti!lce il"i!-.!CIC;;!I
(ru©f:)
to,er!ace ite.x•• (PRO::;)
ta,er:!'ace iten• (i!\AJiJ
[ot@rt!!lce
Ue..xic.!I (LlmA.)
ccrr Cont>m1 Co:,pe•J. c.e ite.•••
C'!ilDC n..n .. 1 t-100• to� C1>a11;e llo
Obj ct
Object Hime
1
p
Trarnsl.11:i:in
soor,ee IAl\guag�
e�JJS0 Engi!h U'>
T;,rg�t �mgwge
� Gl'llNnDE
Figure 55: Translation of CDS Views
70
© Copyright. All rights reserved.
Lesson: Using ABAP Annotations in CDS Views
The values of text annotations are stored in special tables that have a language key and that
are translatable. The value specified in the source code should consist of text in the original
language of the CDS source code and is translated into the required languages.
Translation of CDS Views is done as usual in the Translation Editor (Transaction Code SE63).
A new object type CDS View has been added to object group User Interface Texts.
To translate the texts defined in a given DDL Source, proceed as follows:
1. Start Transaction SE63.
2. Choose Short Texts from the toolbar.
3. On the next dialog window, expand node User Interface Texts.
4. Choose subelement DDLS CDS Views.
5. On the next dialog window, enter the name of the DDL Source, the source language, and
the target language
6. Choose Edit.
Dynamic Access to Annotation Texts
REPORT s4d430d_dynamio_acoess_to_text.
DATA gv_txt TYPE string.
PARAMETERS:
pa eds TYPE ddstrucobjname DEFAULT 'S4D430_ANNOTATIONS',
pa_;elem TYPE ddfieldname_l DEFAULT 'CARRIO',
pa_lang TYPE sy-langu DEFAULT 1EN1 •
=
gv txt
c::l_dd_ddl_annotation_service=>get_label_4_element(
EXPORTING
entityname
pa_ods
elem.entname
pa_elem
� pa_lang
language
=
) .
.. I
Figure 56: Dynamic Access to Text
The methods of global class CL_DD_DDL_ANNOTATION_SERVICE read the texts as specified
by an input parameter for the language.
If no language is passed to the input parameter, the logon language is used as the default.
I»
Note:
If no text is found for the language, the secondary language in AS ABAP is used.
© Copyright. All rights reserved.
71
Unit 2: Basic SQL Features in CDS Views
72
© Copyright. All rights reserved.
Unit 2
Exercise 5
Use Annotations in DDL Sources
Business Example
Template:
S4D430_JOIN_AND_SELECTION (DDL Source)
Solution:
S4D430_ANNOTATIONS (DDL Source)
Create a copy of a DDL Source
For the next exercise, you need a copy of your solution of the previous exercise (DDL Source
Z##_JOIN_AND_SELECTION). If you did not complete the previous exercise, you can copy
from DDL Source S4D430_JOIN_AND_SELECTION.
Note:
ADT does not yet support a Duplicate function for DDL Sources. If you want to
create a copy, you have to create a new DDL Source, first. You then can copy and
paste the source code manually.
1. In your own Package, create a new DDL Source (suggested name: Z##_ANNOTATIONS,
where ## stands for your group number) based on template defineView.
0
Hint:
Even though you want to copy from another DDL Source, it is advisable to
create the DDL Source based on template defineView. This ensures that the
name of the CDS View and the name of the DDL Source correspond to each
other and that the short description of the DDL Source matches the text in
annotation @EndUserText.label.
2. In the new DDL Source, provide a suitable name for the DB View (suggested name:
Z##ANNO).
3. Open the DDL Source you want to duplicate and copy the FROM clause, the field list, and
the WHERE clause to the new DDL Source.
Switch on buffering
1. In the DDL Source, add the relevant annotations to activate buffering. Set the buffering
type to “Generic Buffering”. Make sure that all bookings on the same flight date are
buffered together.
© Copyright. All rights reserved.
73
Unit 2: Basic SQL Features in CDS Views
2. How many key fields do you have to specify to achieve this?
3. Activate the DDL source.
4. Open the SQL View and check the technical settings.
Assign currency key and unit fields to all amount and quantity fields
1. Use the relevant field annotations to link the fields amount and currency.
2. Use the relevant field annotations to link the fields luggweight and wunit.
Activate and Test
1. Activate the DDL Source.
2. Open the Data Preview for the CDS View and ensure that the displayed data are correct.
74
© Copyright. All rights reserved.
Unit 2
Solution 5
Use Annotations in DDL Sources
Business Example
Template:
S4D430_JOIN_AND_SELECTION (DDL Source)
Solution:
S4D430_ANNOTATIONS (DDL Source)
Create a copy of a DDL Source
For the next exercise, you need a copy of your solution of the previous exercise (DDL Source
Z##_JOIN_AND_SELECTION). If you did not complete the previous exercise, you can copy
from DDL Source S4D430_JOIN_AND_SELECTION.
Note:
ADT does not yet support a Duplicate function for DDL Sources. If you want to
create a copy, you have to create a new DDL Source, first. You then can copy and
paste the source code manually.
1. In your own Package, create a new DDL Source (suggested name: Z##_ANNOTATIONS,
where ## stands for your group number) based on template defineView.
0
Hint:
Even though you want to copy from another DDL Source, it is advisable to
create the DDL Source based on template defineView. This ensures that the
name of the CDS View and the name of the DDL Source correspond to each
other and that the short description of the DDL Source matches the text in
annotation @EndUserText.label.
a) See the corresponding step in the previous exercise.
2. In the new DDL Source, provide a suitable name for the DB View (suggested name:
Z##ANNO).
a) See source code extract from the model solution.
3. Open the DDL Source you want to duplicate and copy the FROM clause, the field list, and
the WHERE clause to the new DDL Source.
a) Locate the DDL Source you want to copy from in the Project Explorer (e.g. by adding
the package to your favorites or by searching for it).
b) Open the DDL Source in the editor window by double-clicking on it.
© Copyright. All rights reserved.
75
Unit 2: Basic SQL Features in CDS Views
c) Select the source code you want to copy.
d) Hit Ctrl + C to copy the source code to the clipboard.
e) Open the new DDL Source in the editor window.
f) Select the source code you want to replace and hit
Ctrl + V.
g) See source code extract from the model solution.
Switch on buffering
1. In the DDL Source, add the relevant annotations to activate buffering. Set the buffering
type to “Generic Buffering”. Make sure that all bookings on the same flight date are
buffered together.
a) See source code extract from the model solution.
2. How many key fields do you have to specify to achieve this?
4 (MANDT, CARRIO, CONNID,FLDATE)
3. Activate the DDL source.
a) See the corresponding step in the previous exercise.
4. Open the SQL View and check the technical settings.
a) Locate the SQL View (Z##ANNO) in the
the view in the ABAP Dictionary tool.
b) On the SAP GUI Window, choose
buffer settings.
Project Explorer and double-click on it to open
Menu → Goto → Technical Settings
to display the
Assign currency key and unit fields to all amount and quantity fields
1. Use the relevant field annotations to link the fields amount and currency.
a) See source code extract from the model solution.
2. Use the relevant field annotations to link the fields luggweight and wunit.
a) See source code extract from the model solution.
Activate and Test
1. Activate the DDL Source.
a) See the corresponding step in the previous exercise.
2. Open the Data Preview for the CDS View and ensure that the displayed data are correct.
a) See the corresponding step in the previous exercise.
DDL Source S4D430_ANNOTATIONS
@AbapCatalog.sqlViewName: 'S4D430_ANNO'
@AbapCatalog.compiler.compareFilter: true
@AccessControl.authorizationCheck: #CHECK
@EndUserText.label: 'Solution: ABAP Annotations'
@AbapCatalog.buffering.type: #GENERIC
@AbapCatalog.buffering.numberOfKeyFields: 4
@AbapCatalog.buffering.status: #ACTIVE
76
© Copyright. All rights reserved.
Lesson: Using ABAP Annotations in CDS Views
define view S4D430_Annotations as select
from sbook as b inner join scustom as c
on b.customid = c.id
{ key b.carrid,
key b.connid,
key b.fldate,
key b.bookid,
b.class,
b.forcuram as amount
@<Semantics.amount.currencyCode:'CURRENCY',
b.forcurkey as currency
@<Semantics.currencyCode: true,
b.luggweight
@<Semantics.amount.currencyCode: 'WUNIT',
b.wunit
@<Semantics.currencyCode: true,
b.order_date,
b.agencynum,
b.counter,
b.customid,
c.name,
c.street,
c.postcode,
c.city,
c.country
}
where cancelled <> 'X'
© Copyright. All rights reserved.
77
Unit 2: Basic SQL Features in CDS Views
LESSON SUMMARY
You should now be able to:
78
●
Use ABAP Annotations in CDS Views
●
Work with Translatable Texts in CDS
© Copyright. All rights reserved.
UNIT 3
More SQL Features in CDS
Views
Lesson 1
Using SQL Expressions in CDS Views
Exercise 6: Use Expressions in a CDS View
80
87
Lesson 2
Using Built-in SQL Functions in CDS Views
Exercise 7: Use Built-in Functions in a CDS View
93
101
Lesson 3
Understanding Nested Views
Exercise 8: Define a CDS View based on other CDS Views
107
109
Lesson 4
Using Aggregations in CDS Views
Exercise 9: Define a CDS View with Aggregation
116
121
Lesson 5
Using Additional Join Types and UNION (ALL)
Exercise 10: Define a CDS View with a UNION statement
126
137
UNIT OBJECTIVES
●
Use SQL Expressions in CDS Views
●
Use Built-in SQL Functions in CDS Views
●
Define CDS Views Based on Other CDS Views
●
Use Aggregate Functions, Group By And Having in CDS Views
●
Understand Additional Join Types
●
Understand UNION and UNION ALL
© Copyright. All rights reserved.
79
Unit 3
Lesson 1
Using SQL Expressions in CDS Views
LESSON OBJECTIVES
After completing this lesson, you will be able to:
●
Use SQL Expressions in CDS Views
Literals
Character Uterals
I ...
'Hello'
as c::oI_charJ
'32768' as col_numcJ
I ...
I /Type CHAR
I /Type NUMC (only digits)
Numeric Uterals
I ...
255
col_int4lJ //Type INT4
col_int2J //Type INT2 in Range [-32768,32767]
as c::ol_intlJ //Type INT! in Range [0,255]
1.5
as
32768
4711
L··
as
as
col_fltp, //Type FLTP
Literals with Domain Prefix
r
l
I
...
#S_CLASS. Y' as col _ecol, //S_CLASS is a domain in DDIC
#S_CLASS.Y
as col _eco2, //S_CLASS has fixed values
:S_CLASS.Y
as col _eco3 I /Value 'V' checked by syntax check
...
Figure 57: Literals
ABAP CDS syntax offers the following types of literals:
Character Literals
●
Series of characters enclosed in single quotes
●
Type NUMC if it consists only of digits
●
Type CHAR otherwise
Numeric Literals
80
●
Series of digits without quotes
●
May contain a decimal point, but not before the first digit
© Copyright. All rights reserved.
Lesson: Using SQL Expressions in CDS Views
●
Type FLTP if it contains a decimal point
●
Type INT1, INT2 or INT4 otherwise, depending on the size
I»
Note:
There are no numeric literals of type INT8. This means that integer literals must lie
in the value range of INT4.
Domain Prefixes for Literals
In certain operand positions, a literal can have a domain prefix. A domain prefix consists of the
name of a repository object of type DOMAIN, introduced with character "#" or ": "and
separated by a period (".").
For most of the text literals, the quotes can be omitted when they are prefixed with a domain.
If a literal is prefixed with a domain, syntax check will issue a warning in case the literal does
not match the fixed values of the domain or does not lie in the value range specified by the
domain.
CASE Distinction
Simple Case Di.stinction
CASE operand
WHEN operandl THEN resultl
[WHEN operand2 THEN result2]
[El.SE resultn]
END
• Comparable toABAPSlatementCASE ... WHEN ... ENOCASE.
• Result depends on a series nf "EQUALS"-comparisons
Complex Case Distinction(= Searched Case)
CASE WHEN s.ql_co11ditionl THEN resuLtl
[WHEN sql_condition2 THEN result2]
[ElSE resultn]
END
• Comparable toABAP Statement IF ... ELSEIF .... ENDIF.
• Result depends on a sequence of SQL conditions (logical expressions)
.. I
Figure 58: Case Distinctions
ABAP CDS offers case distinctions that can be used in the element list of a SELECT statement
and as operands for other expressions.
A case distinction returns exactly one value. This value depends on a series of conditions.
A case distinction always starts with key work CASE and ends with key word END. The rest
depends on the type of case distinction:
Simple Case Distinction
The result depends on the values of several operands. The simple case distinction is
comparable to the CASE statement in ABAP.
© Copyright. All rights reserved.
81
Unit 3: More SQL Features in CDS Views
Complex Case Distinction
Also known as searched distinction.
The result depends on a sequence of logical expressions. The complex case distinction is
comparable to the IF statement in ABAP.
l@AbapCatalog. sqlViewNlame: 'S4D430_ EXPRCASE'
define view S4d430 _Expression_Case as select
from sboolk
I
{
...
II Simple Case
case class
...
whe11 'Y' then 'Economy'
when 'C' then 'Business'
when 'FI then 'First'
end
as class _txt
}
]
Figure 59: Example 1: A Simple Case Expression
The figure above gives an example of a simple case distinction in a CDS View.
Field CLASS of table SBOOK is of type CHAR length 1 and can have three different values. To
make this more readable, the case distinction replaces the technical one-character key with a
longer text.
Note:
If, like in the example above, the ELSE branch is missing, syntax check will issue a
warning.
82
© Copyright. All rights reserved.
Lesson: Using SQL Expressions in CDS Views
l@Abap(atalog .. sqlViewN1ame: '540430_ EXPRCASE'
define view S4d430_Expression __case as select
from sboolk
I
{
...
II Complex Case
case
=
=
wunit
=
,,
when class
when wunit
when
else
'F'
then
and luggweight ) 20 then 'X'
'LB' and luggweight > 44 then 'X'
'KG'
I
as excess_luggage1,
end
...
I
I
}
Figure 60: Example 2: A Complex Case Expression
The figure above gives an example of a complex case distinction in a CDS View.
Customers with a luggage weight larger than 20 kilogram or 44 pound will be classified as
having excess luggage. First class passengers, however, are always excluded from this
classification.
I @Abap(atalog. sqlViewName:
'S4D430_EXPRCASE'
define view S4d430_cxpression_:Case as select
from sboolk
{
II Nested case
case dass
when 'F' thern
else case
when ( wunit .... 'KG' and luggweight > 20
or ( wunit
then 'X'
else
'LB' and
luggweight >
then 'X'
44
'X'
end
end
as excess_luggage2
}
Figure 61: Example 3: Two Nested Case Expressions
The figure above gives an example of nested case distinctions in a CDS View.
The outer CASE expression checks whether this is a first class booking.
The result in the ELSE branch of the outer CASE expression is not just literal but it consists of
another case expression based on the luggage weight and unit.
Of course, also the result after a WHEN … THEN branch could be a case expression.
© Copyright. All rights reserved.
83
Unit 3: More SQL Features in CDS Views
Arithmetic Expressions
Four arlthmetlc opera.t.ors (+, -, ", /) and brackets
Three Types of C:.xp:ressions
• Integer Expression
- All Operands have integer type (INT1, INT2, INT4, INTS)
• D'eeimal Expression
- At least one operand has decimal type (DEC, CURR, QUAN)
- No operand of type FLTP
• Floating Point Expression
- All operands have type FLTP
Important Rest,rictions
• If one operand has type FLTP, all operands require type FLTP
Operator "I" only allowed in floating point expressions
I
J
See next section for the possibility of type conversions
I
Figure 62: Arithmetic Expressions
In ABAP CDS, arithmetic expressions can be used as elements of the field list.
ABAP CDS supports four operators, brackets and three different arithmetics (integer,
decimal and floating point). The value range and precision of intermediate results highly
depends on the arithmetic that is used.
Note:
Numeric literals without decimals have integer type. Numeric Literals with decimals have type
FLTP!
l@Abap(atalog.
sqlViewNlame: 'S4D430_ EXPRARITH'
define view s4d430 _Expression_ arithmetic as select
from sf ight
{
seatsmax,
saat socc ,
seatsmax - seatsocc
as seatsfree,
seatsocc + seatsocc_ b + seatsocc -f as seatsmax_tot,
2 * price
as double_price
I}
I
Figure 63: Example: Arithmetic Expressions in CDS Views
The figure above gives some examples for arithmetic expressions in CDS Views.
84
© Copyright. All rights reserved.
Lesson: Using SQL Expressions in CDS Views
Type Conversions
• What. it looks I i,ke:
CAST (
operand AS target_ type )
What it does:
- Converts the value of operand into target_type
Two Options for target_type:
A predefined dictionary type, e.g. abap. i.nt4, abap. char-(19),, abap. dec(S,, 2)
Any Dictionary data element, e.g. 5_CARRID, 8UKRS
Many Options for operand:
Literal (without a domain prefix)
Field
or a data source
- Arithmetic expression
- Case distinction with CASE
- Predefined function
]
Figure 64: Type Conversion with CAST Expression
Unlike ABAP, ABAP CDS does not know implicit type conversions. On the contrary, CDS
inspects very strict type compatibility rules.
The CAST expression of CDS allows you to implement explicit type conversions.
In NW 7.40, the target type could only be specified as technical type, i.e., as a predefined
Dictionary type like INT4, CHAR or DEC.
As of NW 7.50, any data element from the Dictionary can be the target type of a type
conversion with CAST.
The operand for a type conversion cannot only be a literal or a field of the data source (for
example, of a database table). All kinds of other expressions are possible like arithmetic
expressions, CASE distinctions, predefined functions, and many others.
Note:
There are restrictions with regard to the combination of source type and target type. Some
combinations are not supported at all. Others only work with limitations. For example, it is
currently not possible to use operands of type FLTP as source for the CAST expression. A
detailed matrix can be found in the ABAP Language documentation.
© Copyright. All rights reserved.
85
Unit 3: More SQL Features in CDS Views
@AbapCatalog. sqlViewName:
'S4D430_EXPIRCAST'
define view S4d430_Expression_cast as select
from sf light
{
'19891109'
as col_char,
cast(' 19891109' as abap. int4)
cast(' 1989U09' as abap.dec(l6,.2))
cast(' 19891109' as abap.fltp)
as col_int4.,
as col_dec,
as colJltp,
cast('19891109' as abap.Bats )
as coL_datsJ
cast( castt ' 19891109' as abap .. dats) as s_date) as col_ddic.,
cast(seatsocc as abap.fl tp) I cast(seatsmax as abap.fltp)
as ratio
}
cot�hu
!1m1100
19891100
,;;oljrrtA
19.891.109
1i:i.&11.109
col_dK
19891109.00
19891109.00
col_fllp
1. 989'1109000000000E·07
1. 989rl 109000000000£�01
tr.t)('l,ii�.r,.,.
I
col_dm
19S9·1Ml9
1989·'11·09
col_ddi<;
1989·11·09
1989·11-09
r.tliii
9. 702 S9740259740lE·01
9.fl62ll766233J6622E-01
I
,.",.,,:..,""'l '),,.,","1:11"1.'i
Figure 65: Example: Type Conversions With CAST
The figure above gives some examples of type conversions in CDS Views.
86
© Copyright. All rights reserved.
Unit 3
Exercise 6
Use Expressions in a CDS View
Business Example
Template:
S4D430__ANNOTATIONS (DDL Source)
Solution:
S4D430_EXPRESSIONS (DDL Source)
Create a copy of your DDL Source
For the next exercise, you need a copy of your solution of the previous exercise (DDL Source
Z##_ANNOTATIONS). If you did not complete the previous exercise, you can copy from DDL
Source S4D430_ANNOTATIONS.
1. In your own Package, create a new DDL Source (suggested name: Z##_EXPRESSIONS,
where ## stands for your group number) based on template defineView.
2. In the new DDL Source, provide a suitable name for the DB View (suggested name:
Z##EXPR).
3. Open the DDL Source you want to duplicate and copy the FROM clause, the field list and
the WHERE clause to the new DDL Source.
Return readable text for the flight class
Field CLASS of table SBOOK contains a single character key for the flight class of the booking.
Possible values are “Y”, “C” and “F”. Use the CASE expression to return longer texts for the
three flight classes.
1. In the field list, replace field CLASS with a simple CASE expression to return texts
“Economy”, “Business” and “First” instead of values “Y”, “C” and “F”.
Return the customer’s discount as a factor
Field DISCOUNT of table SCUSTOM contains a customer-specific discount rate. This discount
rate is stored as an integer number between 0 and 100. Implement an arithmetic expression
to return the discount as a value between 0.00 and 1.00 instead.
1. Use an arithmetic expression with operator “/” to divide the discount value by 100.
Why do you have to cast the discount value to another data type?
2. Use the respective annotations to provide a label and a tooltip for the calculated discount
field.
Activate and Test
© Copyright. All rights reserved.
87
Unit 3: More SQL Features in CDS Views
1. Activate the DDL Source.
2. Open the Data Preview for the CDS View and ensure that the displayed data are correct.
88
© Copyright. All rights reserved.
Unit 3
Solution 6
Use Expressions in a CDS View
Business Example
Template:
S4D430__ANNOTATIONS (DDL Source)
Solution:
S4D430_EXPRESSIONS (DDL Source)
Create a copy of your DDL Source
For the next exercise, you need a copy of your solution of the previous exercise (DDL Source
Z##_ANNOTATIONS). If you did not complete the previous exercise, you can copy from DDL
Source S4D430_ANNOTATIONS.
1. In your own Package, create a new DDL Source (suggested name: Z##_EXPRESSIONS,
where ## stands for your group number) based on template defineView.
a) See the corresponding step in the previous exercise.
2. In the new DDL Source, provide a suitable name for the DB View (suggested name:
Z##EXPR).
a) See source code extract from the model solution.
3. Open the DDL Source you want to duplicate and copy the FROM clause, the field list and
the WHERE clause to the new DDL Source.
a) See the corresponding step in the previous exercise.
Return readable text for the flight class
Field CLASS of table SBOOK contains a single character key for the flight class of the booking.
Possible values are “Y”, “C” and “F”. Use the CASE expression to return longer texts for the
three flight classes.
1. In the field list, replace field CLASS with a simple CASE expression to return texts
“Economy”, “Business” and “First” instead of values “Y”, “C” and “F”.
a) See source code extract from the model solution.
Return the customer’s discount as a factor
Field DISCOUNT of table SCUSTOM contains a customer-specific discount rate. This discount
rate is stored as an integer number between 0 and 100. Implement an arithmetic expression
to return the discount as a value between 0.00 and 1.00 instead.
1. Use an arithmetic expression with operator “/” to divide the discount value by 100.
© Copyright. All rights reserved.
89
Unit 3: More SQL Features in CDS Views
Why do you have to cast the discount value to another data type?
Because operator “/” only supports type abap.fltp.
a) See source code extract from the model solution.
2. Use the respective annotations to provide a label and a tooltip for the calculated discount
field.
a) See source code extract from the model solution.
Activate and Test
1. Activate the DDL Source.
a) See the corresponding step in the previous exercise.
2. Open the Data Preview for the CDS View and ensure that the displayed data are correct.
a) See the corresponding step in the previous exercise.
DDL Source S4D430_EXPRESSIONS
@AbapCatalog.sqlViewName: 'S4D430EXPR'
@AbapCatalog.compiler.compareFilter: true
@AccessControl.authorizationCheck: #CHECK
@EndUserText.label: 'Solution: Expressions'
define view S4D430_Expressions as select
from sbook as b inner join scustom as c
on b.customid =
c.id
{ key b.carrid,
key b.connid,
key b.fldate,
key b.bookid,
case b.class
when 'Y' then 'Economy'
when 'C' then 'Business'
when 'F' then 'First'
else '???'
end as class,
b.forcuram as amount
@<Semantics.amount.currencyCode:'CURRENCY',
b.forcurkey as currency
@<Semantics.currencyCode: true,
b.luggweight
@<Semantics.amount.currencyCode: 'WUNIT',
b.wunit
@<Semantics.currencyCode: true,
b.order_date,
b.agencynum,
b.counter,
b.customid,
c.name,
c.street,
c.postcode,
c.city,
c.country,
@EndUserText.label: 'Discount Factor'
@EndUserText.quickInfo: 'Customer Specific
Discount Factor'
90
© Copyright. All rights reserved.
Lesson: Using SQL Expressions in CDS Views
cast(c.discount as abap.fltp(16,16)) / 100.0
as discount
}
where cancelled <> 'X'
© Copyright. All rights reserved.
91
Unit 3: More SQL Features in CDS Views
LESSON SUMMARY
You should now be able to:
●
92
Use SQL Expressions in CDS Views
© Copyright. All rights reserved.
Unit 3
Lesson 2
Using Built-in SQL Functions in CDS Views
LESSON OBJECTIVES
After completing this lesson, you will be able to:
●
Use Built-in SQL Functions in CDS Views
Arithmetic Functions
ABAP CDS offers a variety of built-in functions that supplement calculations with arithmetic
expressions.
Built-in Functions for Calculations
• div(arg1,arg2)
- Input: Only integer values
(INT1, INT2, INT4, INTS or DEC, CURR, QUAN with decimals= 0)
- Result type: type of arg 1
- Result a I ways rounded to integer value
• mod(arg1,arg2)
- Input Only integer types (INT1, INT2, INT4, INTS)
- Result type: type of arg1
- Result can be negative
• division(arg1, arg2, dee)
- Input Integer values, values with fixed decimal
(Types INT1, INT2, INT4, INT8 and DEC, CURR, QUAN with any number of decimals)
- Result type: DEC with dee decimal places, length depends on type of a,gl
- Result is always rounded to dee decimals
Figure 66: Numeric Functions (1)
The main differences between functions div( ) and division( ) are as follows:
Input:
Div( ) only allows integer values as input. Division( ) only excludes floating point numbers
(binary or decimal).
Result:
Div( ) always returns an integer value as result. Division( ) allows you to specify the
precision of the result.
© Copyright. All rights reserved.
93
Unit 3: More SQL Features in CDS Views
Note:
With respect to the signs, functions div( ) and mod( ) behave differently than the
ABAP operators DIV and MOD.
In SQL function div( ), the amounts of the arguments are divided and then the
sign is assigned (positive if the arguments have the same signs, and negative if
they have different signs). Accordingly, the result of MOD can be negative. The
ABAP operator MOD, on the other hand, only produces positive results.
Ill
Built-in Rounding Functions
abs(arg)
abs( 1.5)::!l 1
- returns the absolut amount of arg,
abs( -1.5)
=
-1
flo,or( 1.5)
floor( -1.5)
=
=
-2
ceil( 1.5)
ceil( �1.5)
=
=
�1
i.e always rounds towards zero
• floor(arg),
- rounds to the next lower integer
i.e. towards zero ifarg > 0, away from zero ifarg < 0
ceil(arg),
- rounds to the next higher integer
i.e. away from zero if arg > 0, towards zero if a rg < 0
1
2
• round(arg,pos),
- pos > 0: Round arg to pos decimal places
- pos -c
I
o:
Round arg to position
round(3 .. 1514, 2)
round(273.15,-1)
= 3.15
= 270
Figure 67: Numeric Functions (2)
String Functions
ABAP CDS offers a variety of built-in functions for string processing. Some of them were
already available in release NW 7.40, some others are new in NW 7.50.
94
© Copyright. All rights reserved.
Lesson: Using Built-in SQL Functions in CDS Views
Some Built-in Functions for String Processing (NW 7.40)
concat(arg1 ,arg2)
- Returns resu It of type CHAR or SSTR I NG (depending on types of arg 1 and arg2)
- All trailing blanks are removed
- Corresponds toABAP statement CONCATENATE without addition SEPJmATED BY
replace{arg1, arg2, arg3)
- Result type depends on type of arg1
- corresponds to ABAP statement
REPLACE ALL OCCURENCES OF arg2 IN arg1 RITH arg3.
substri ng(arg,p·os,len)
- Result type depends on type of arg
- Similar to ABAP function substring[) or direct substring access: dobj [ +off] [ ( lenl I
Important difference: pos denotes the position not the offset!
.. J
•
Figure 68: String Processing Functions(1)
The figure shows some important string functions available as off NW 7.40. A complete list
can be found in the ABAP language help.
Some Built.in Functions for String Processing (NW 7.50)
concat_with_spa.ce(arg1,arg2,count)
- Like concat( ) but with count spaces between arg1 and arg2
- Similart:oABAP statement CONCATENATEWithaddition
SEPARATED BY
• length(arg)
- Returns resu It of type I NT 4
- Trailing blanks do not count
- Corresponds to ABAP built-in fu net ion n umof char < )
• left,(arg,n) and right(arg,n)
- Similar to substring(), but returns first or last n characters of arg
- left{ ) corresponds to ABAP expression arg ( n)
l
Figure 69: String Processing Functions(2)
In NW 7.50 the existing functions for string processing were supplemented to fill gaps and to
cover special cases.
The figure shows some examples. A complete list can be found in the ABAP language help.
Note:
Built-in functions can be chained at will.
This was actually used quite often, when in NW 7.40 function concat_with_space
was not yet available. The solution based on function concat looked like this:
concat(concat(arg1,' '),arg2)
© Copyright. All rights reserved.
95
Unit 3: More SQL Features in CDS Views
I @AbapCatalog. sqlViewNlame:
'S4D430_FUNCCHAR,
define view s4d430 - Function_strirng as select
from scarr
{
car-r-Id,
carrname,
concat(carrid,carrname)
as col _concat,
concat_with_space(carrid,carrname,3)
as col con cat _space,
replace(carrname, 'HaNs', 'fritz')
as col _replace,
substring(carrname,5,4)
as col _substring,
length (car-r-Id) as col _length
II
II
II
=> 'LH
=> 'Lufthansa'
-=> 'l.H1ufthansa'
II
=> 'LH
II
=> 'Luftfritza'
II
=> 'hans'
Lufthansa'
II => 2 (trailing blank!)
}
where carrname = 'Lufthansa'
I
Figure 70: Example: String Processing in a CDS View
The figure above gives some examples of string processing in CDS Views.
Note:
●
●
●
The second argument of function replace( ) is upper-case but content of
carrname is lower-case.
The second argument of function substring( ) is 5, not 4!
Function length( ) returns value 2 because the third character in CARRID is a
trailing blank
Coalesce
Currency and Unit Conversion
Amounts and measurements are usually stored on the database in a source unit and source
currency. To make values in different units or currencies comparable with each other, they
need to be converted.
Traditionally, we do these conversions with standard function modules provided by SAP (e.g.
UNIT_CONVERSION_SIMPLE or CONVERT_TO_LOCAL_CURRENCY).
96
© Copyright. All rights reserved.
Lesson: Using Built-in SQL Functions in CDS Views
Built-in functions
• Unit_Conversion(p1 => al, p2 => az , .•• )
- Returns result of type abap.quan
- Converts a quantity in source unit into a value in target unit
- Ru less maintained in transaction CUNI and stored in database table T()()6
• Currency_conversion(pl => a1, p2 => a2, .•• )
- Returns result of type abap.curr
- Converts an amount in source currenoy into a value in target currency
- Based on the exchange rale valid on a target date
- Rules maintained in transaction OB08 and stored in database tables TCUR ....
General Remairks
- Pcarameter assignment with operator "=>"
- Komma-separated Parameters
- Optional parameter error_handling with default value "FAIL_ON_ERROR"
Other options: "SET_TO_NULL" and "KEEP_UNCONVERTED"
- Result may depend on the database (different rounding rules)
,I Figure 71: Currency and Unit Conversions
The function modules make use of conversion rules that are maintained in standard
transactions and stored in (client-dependent) tables.
ABAP CDS allows you to move the conversions from the ABAP stack onto database level. Two
built-in functions are available to implement conversions in the DDL Source.
Note:
Although the built-in functions use the same rules and logic as the corresponding
ABAP function modules, you must not expect the exact same results. This is
obvious when you take into consideration that different rounding rules may apply
for calculations on the database and for calculations in ABAP.
@Abapcata og. sqlV' ewNlame:
'S4D430_FUNCCONrV1'
define view S4d430_Function_Convertion1 as select
from spfli
{ carrid,
connid,
@Semant ·cs.quantity .un · tOfMeasure:
Casting of literal 'Ml'
into expected type
'DIST ID'
Unit_C:onversion( quantity
=> distance,
source_unit => distid,
target_unit => cast( 'MI' as abap.uni:t)
) as distance,
@Semant"cs.unitOfMeasure: true
cast( 'MI' as abop , unit) as distid
Parameter assignment
with operator .,=>"
Figure 72: Example: Unit Conversion From Kilometers to Miles
Database table SPFLI contains a field DISTANCE in which the flight distance is stored for each
flight connection. The corresponding unit of measure is found in field DISTID.
© Copyright. All rights reserved.
97
In the CDS View definition above, the value in table field DISTANCE is converted into miles
("MI") and returned as view field DISTANCE. Literal "MI" is returned as view field DISTID.
Semantics annotations are used to link the two view fields to each other.
Note:
The text literal has to be converted into ABAP Dictionary type Unit twice: To make
it compatible with input parameter target_unit and to make use of annotation
Semantics.unitOfMeasure.
@AbapCatalog. sqlViewName:
'S4D430_FUNCCONrV2'
define view s4d430_Function_Conversion2 as select
from sfliglht
{ carrid,
connid,
fldate,
@Semantics. amount. c ur-r-encyccde: 'CURRENCY'
currency_conve,rsion (
aa) price,
amount
source_currency
round
=> currency,
=> 'X''
target_currency
exchange_rate_type
exchange_rate_;date
aa)
error_handling
=>
aa)
aa)
Casting of literal 'USO'
into expected type
cast( 'USO' as abap. cuky),
'M''
fldate.,
I
SET_ TO_NUILL
I
) as price,
@Semantics.cu rren cyCode: true
cast(' USD' as abap . cuny ) as currency
}
Behaviour in Case
of error
Figure 73: Example: Currency Conversion
Database table SFLIGHT contains a field PRICE in which the standard ticket price is stored for
each flight. The corresponding currency code is found in field CURRENCY.
In the CDS View definition above, the value in table field PRICE is converted into US Dollar
("USD") and returned as view field PRICE. Literal "USD" is returned as view field CURRENCY.
Semantics annotations are used to link the two view fields to each other.
Note:
The text literal has to be converted into ABAP Dictionary type CUKY twice: To
make it compatible with input parameter target_currency and to make use of
annotation Semantics.currencyCode.
ERROR: stackunderflow
OFFENDING COMMAND: ~
STACK:
Unit 3: More SQL Features in CDS Views
With other options, you can make the function return the NULL value, the initial value
('00000000') or the unaltered input value.
100
© Copyright. All rights reserved.
Unit 3
Exercise 7
Use Built-in Functions in a CDS View
Business Example
Template:
S4D430_EXPRESSIONS (DDL Source)
Solution:
S4D430_FUNCTIONS (DDL Source)
Create a copy of your DDL Source
For the next exercise you need a copy of your solution of the previous exercise (DDL Source
Z##_EXPRESSIONS). If you did not complete the previous exercise you can copy from DDL
Source S4D430_EXPRESSIONS.
1. In your own Package, create a new DDL Source (suggested name: Z##_FUNCTIONS,
where ## stands for your group number) based on template defineView.
2. In the new DDL Source, provide a suitable name for the DB View (suggested name:
Z##FUNC).
3. Open the DDL Source you want to duplicate and copy the FROM clause, the field list and
the WHERE clause to the new DDL Source.
Use String Function concat_with_space( )
1. In the field list, replace the name of the flight customer (field NAME) with string function
concat_with_space( ) to concatenate the two fields SALUTATION and NAME.
Note:
This function is available as of AS ABAP 7.50. In AS ABAP 7.40 a nested call of
function concat( ) had to be used to achieve the same result.
Use Arithmetic Function division( )
1. In the calculation of the discount, replace the arithmetic expression with arithmetic
function division( ). Make sure the result is given with two decimal places.
2. What is the advantage of using this function?
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101
Unit 3: More SQL Features in CDS Views
3. Do you still need to cast the value of field discount befor you can use it as input for the
function?
Perform a Currency Conversion
Use function currency_conversion( ) so that field AMOUNT returns the booking price in
currency USD (US Dollar).
1. In the field list, replace field loccuram with a call of built-in function
currency_conversion( ).
Hint:
Use the editor’s auto-completion capabilities to generate the function call
and parameter list.
2. Use fields LOCURRAM and LOCURKEY as input values for parameters source_amount and
source_currency.
3. Set the target currency to literal value “USD.”
Why is the literal “USD” itself not compatible with the functions input parameter
target_currency?
4. Choose exchange rate type “M” and do the calculation based on the exchange rate that
was valid on the day of booking (field ORDER_DATE).
5. Make sure that for all bookings, field currency returns the literal “USD” rather than the
value of table field LOCURKEY.
Calculate the Number of Days between two Dates
Calculate the number of days between the purchase of the ticket (field ORDER_DATE) and the
actual flight date (field FLDATE).
1. In the field list, add a new field after the field ORDER_DATE (suggested name:
DAYS_AHEAD). Use function dats_days_between( ) to calculate the number of days
between the date fields FLDATE and ORDER_DATE
Activate and Test
1. Activate the DDL Source.
2. Open the Data Preview for the CDS View and ensure that the displayed data are correct.
102
© Copyright. All rights reserved.
Unit 3
Solution 7
Use Built-in Functions in a CDS View
Business Example
Template:
S4D430_EXPRESSIONS (DDL Source)
Solution:
S4D430_FUNCTIONS (DDL Source)
Create a copy of your DDL Source
For the next exercise you need a copy of your solution of the previous exercise (DDL Source
Z##_EXPRESSIONS). If you did not complete the previous exercise you can copy from DDL
Source S4D430_EXPRESSIONS.
1. In your own Package, create a new DDL Source (suggested name: Z##_FUNCTIONS,
where ## stands for your group number) based on template defineView.
a) See the corresponding step in the previous exercise.
2. In the new DDL Source, provide a suitable name for the DB View (suggested name:
Z##FUNC).
a) See source code extract from the model solution.
3. Open the DDL Source you want to duplicate and copy the FROM clause, the field list and
the WHERE clause to the new DDL Source.
a) See the corresponding step in the previous exercise.
Use String Function concat_with_space( )
1. In the field list, replace the name of the flight customer (field NAME) with string function
concat_with_space( ) to concatenate the two fields SALUTATION and NAME.
Note:
This function is available as of AS ABAP 7.50. In AS ABAP 7.40 a nested call of
function concat( ) had to be used to achieve the same result.
a) See source code extract from the model solution.
Use Arithmetic Function division( )
1. In the calculation of the discount, replace the arithmetic expression with arithmetic
function division( ). Make sure the result is given with two decimal places.
a) See source code extract from the model solution.
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103
Unit 3: More SQL Features in CDS Views
2. What is the advantage of using this function?
The function supports many different numeric data types as input — not only type
abap.fltp and it returns the result in type abap.dec with the possibility to set the number of
decimal places for the result.
3. Do you still need to cast the value of field discount befor you can use it as input for the
function?
Yes. because the table field has type NUMC which is a character- like data type.
Perform a Currency Conversion
Use function currency_conversion( ) so that field AMOUNT returns the booking price in
currency USD (US Dollar).
1. In the field list, replace field loccuram with a call of built-in function
currency_conversion( ).
Hint:
Use the editor’s auto-completion capabilities to generate the function call
and parameter list.
a) See source code extract from the model solution.
2. Use fields LOCURRAM and LOCURKEY as input values for parameters source_amount and
source_currency.
a) See source code extract from the model solution.
3. Set the target currency to literal value “USD.”
Why is the literal “USD” itself not compatible with the functions input parameter
target_currency?
The parameter expects an input value pf type abap.cuky.
a) See source code extract from the model solution.
4. Choose exchange rate type “M” and do the calculation based on the exchange rate that
was valid on the day of booking (field ORDER_DATE).
a) See source code extract from the model solution.
5. Make sure that for all bookings, field currency returns the literal “USD” rather than the
value of table field LOCURKEY.
a) See source code extract from the model solution.
Calculate the Number of Days between two Dates
Calculate the number of days between the purchase of the ticket (field ORDER_DATE) and the
actual flight date (field FLDATE).
1. In the field list, add a new field after the field ORDER_DATE (suggested name:
DAYS_AHEAD). Use function dats_days_between( ) to calculate the number of days
between the date fields FLDATE and ORDER_DATE
104
© Copyright. All rights reserved.
Lesson: Using Built-in SQL Functions in CDS Views
a) See source code extract from the model solution.
Activate and Test
1. Activate the DDL Source.
a) See the corresponding step in the previous exercise.
2. Open the Data Preview for the CDS View and ensure that the displayed data are correct.
a) See the corresponding step in the previous exercise.
DDL Source S4D430_FUNCTIONS
@AbapCatalog.sqlViewName: 'S4D430FUNC'
@AbapCatalog.compiler.compareFilter: true
@AccessControl.authorizationCheck: #CHECK
@EndUserText.label: 'Solution: Functions'
define view S4D430_Functions as select
from sbook as b inner join scustom as c
on b.customid = c.id
{ key b.carrid,
key b.connid,
key b.fldate,
key b.bookid,
case b.class
when 'Y' then 'Economy'
when 'C' then 'Business'
when 'F' then 'First'
else '???'
end as class,
currency_conversion(
amount => b.forcuram,
source_currency => b.forcurkey,
round => 'X',
target_currency => cast( 'USD' as abap.cuky),
exchange_rate_type => 'M',
exchange_rate_date => b.order_date,
error_handling => 'SET_TO_NULL'
)
as amount @<Semantics.amount.currencyCode:'CURRENCY',
cast('USD' as abap.cuky)
as currency @<Semantics.currencyCode: true,
b.luggweight @<Semantics.amount.currencyCode: 'WUNIT',
b.wunit @<Semantics.currencyCode: true,
b.order_date,
dats_days_between(b.order_date, b.fldate) as days_ahead,
b.agencynum,
b.counter,
b.customid,
concat_with_space(c.form, c.name, 1) as name,
// Workaround in 7.40
// concat(concat( c.form, ' '), c.name) as name,
c.street,
c.postcode,
c.city,
c.country,
@EndUserText.label: 'Discount Factor'
@EndUserText.quickInfo: 'Customer Specific Discount Factor'
division(cast(c.discount as abap.int4), 100, 2) as discount
}
where cancelled <> 'X'
© Copyright. All rights reserved.
105
Unit 3: More SQL Features in CDS Views
LESSON SUMMARY
You should now be able to:
●
106
Use Built-in SQL Functions in CDS Views
© Copyright. All rights reserved.
Unit 3
Lesson 3
Understanding Nested Views
LESSON OBJECTIVES
After completing this lesson, you will be able to:
●
Define CDS Views Based on Other CDS Views
CDS Views Based on Other CDS Views
Up to now, our CDS Views were all based on a single database table or on a join of several
database tables.
In CDS you can also define CDS views that are based on one or more other CDS Views. This is
sometimes referred to as “View on View concept” or as “Nested Views”.
CDS Views as data source of other CDS Views
- Join of CDS Viev.rs and join of CDS View with DB table supported
- No technical limit of nesting depth and complexity
• Improved Re-use
- e.g. calou lation done in one basis view that is used in several other views
instead of coding (and maintaining) identical expressions
• Improved Readability
- e.g. join of 2 Views that contain joins instead of a complicated join of many tables
Figure 76: Nested Views (View on View Concept)
Building Nested Views is another important difference between the classical database views
in ABAP Dictionary and the new CDS Views. The big advantages are the improved re-use of
views and the improved readability.
Note:
Regarding the advantages there is a striking similarity with the advantages of
modularization of source code.
© Copyright. All rights reserved.
107
Unit 3: More SQL Features in CDS Views
Advantages and Pitfalls
• Unintended Circular References
- Ever1tually, all views have to be based on tables
- Circular references are not allowed
- At the moment, circular references lead to
timeouts during activation
• Too many Nesting Levels
- increase the likelihood for recursive
references
- deteriorate the rea.dability of the model
- increase the likelihood for redundancies
Figure 77: Pitfalls of Nested Views
Recommendations
G,roup your views into levels {preferably 3 levels)
Only access views that are assigned to a lower level
I
108
Figure 78: Recommendations for Nested Views
© Copyright. All rights reserved.
Unit 3
Exercise 8
Define a CDS View based on other CDS Views
Business Example
Template:
S4D430_FUNCTIONS (DDL Source)
Solution:
S4D430_BOOKING (DDL Source)
S4D430_CUSTOMER (DDL Source)
S4D430_BOOKING_AND_COSTOMER (DDL Source)
Define a CDS View that returns only the booking-related information
In this exercise you want to define a new CDS View that returns only the booking-related
information from your solution of the previous exercise (DDL Source Z##_FUNCTIONS). If
you did not complete the previous exercise you can copy from DDL Source
S4D430_FUNCTIONS.
1. In your own package, create a new DDL Source (suggested name: Z##_BOOKING, where
## stands for your group number) based on template defineView.
2. In the new DDL Source, provide a suitable name for the DB View (suggested name:
Z##BOOK).
3. In the FROM clause of the SELECT statement specify database table SBOOK as data
source.
4. Open DDL Source Z##_FUNCTIONS (or DDL Source S4D430_FUNCTIONS) and copy the
field list and the WHERE clause to the new DDL Source.
5. Remove everything from the field list, that is based on SCUSTOM.
Hint:
If you specify an alias for table SBOOK you can leave the rest of field list
unchanged.
6. Activate the DDL Source.
Define a CDS View that returns only the customer-related information
In this exercise you want to define a new CDS View that returns only the customer-related
information from your solution of the previous exercise (DDL Source Z##_FUNCTIONS). If
you did not complete the previous exercise you can copy from DDL Source
S4D430_FUNCTIONS.
© Copyright. All rights reserved.
109
Unit 3: More SQL Features in CDS Views
1. In your own package, create a new DDL Source (suggested name: Z##_CUSTOMER,
where ## stands for your group number) based on template defineView.
2. In the new DDL Source, provide a suitable name for the DB View (suggested name:
Z##CUST).
3. In the FROM clause of the SELECT statement specify database table SCUSTOM as data
source.
4. Open DDL Source Z##_FUNCTIONS (or DDL Source S4D430_FUNCTIONS) and copy the
field list to the new DDL Source.
5. Remove everything from the field list, that is based on SBOOK.
Hint:
If you specify an alias for table SCUSTOM you can leave the rest of field list
unchanged.
6. Activate the DDL Source.
Define a CDS View that combines data from the two CDS Views
You now want to define a new CDS View that returns exactly the same information as your
solution of the previous exercise (DDL Source Z##_FUNCTIONS). But instead of reading from
the database tables directly and doing the calculations itself, the new CDS View will read from
two other CDS Views that encapsulate the calculations.
1. In your own Package, create a new DDL Source (suggested name:
Z##_BOOKING_AND_CUSTOMER, where ## stands for your group number) based on
template defineView.
2. In the new DDL Source, provide a suitable name for the DB View (suggested name:
Z##BOOKCUST).
3. Open the DDL Source Z##_FUNCTIONS (or DDL Source S4D430_FUNCTIONS) and copy
the FROM clause, the field list and the WHERE clause to the new DDL Source.
4. In the new DDL Source, edit the FROM clause. Replace tables SBOOK and SCUSTOM with
the two CDS Views you created earlier in this exercise (Z##_Booking and
Z##_Customer).
5. Edit the field list. Remove all components with expressions and functions and replace
them with the corresponding fields of the CDS Views.
Note:
If you copied the WHERE clause, too, don’t forget to remove it. It is superfluous
in Z##_Booking_And_Customer as it is already contained in CDS View
Z##_Booking.
Activate and Test
1. Activate the DDL Sources.
2. Open the Data Preview for CDS View S4D430_BOOKING_AND_CUSTOMER and ensure
that the displayed data are correct.
110
© Copyright. All rights reserved.
Unit 3
Solution 8
Define a CDS View based on other CDS Views
Business Example
Template:
S4D430_FUNCTIONS (DDL Source)
Solution:
S4D430_BOOKING (DDL Source)
S4D430_CUSTOMER (DDL Source)
S4D430_BOOKING_AND_COSTOMER (DDL Source)
Define a CDS View that returns only the booking-related information
In this exercise you want to define a new CDS View that returns only the booking-related
information from your solution of the previous exercise (DDL Source Z##_FUNCTIONS). If
you did not complete the previous exercise you can copy from DDL Source
S4D430_FUNCTIONS.
1. In your own package, create a new DDL Source (suggested name: Z##_BOOKING, where
## stands for your group number) based on template defineView.
a) See the corresponding step in the previous exercise.
2. In the new DDL Source, provide a suitable name for the DB View (suggested name:
Z##BOOK).
a) See source code extract from the model solution.
3. In the FROM clause of the SELECT statement specify database table SBOOK as data
source.
a) See source code extract from the model solution.
4. Open DDL Source Z##_FUNCTIONS (or DDL Source S4D430_FUNCTIONS) and copy the
field list and the WHERE clause to the new DDL Source.
a) See the corresponding step in the previous exercise.
5. Remove everything from the field list, that is based on SCUSTOM.
Hint:
If you specify an alias for table SBOOK you can leave the rest of field list
unchanged.
a) See source code extract from the model solution.
6. Activate the DDL Source.
© Copyright. All rights reserved.
111
Unit 3: More SQL Features in CDS Views
a) See the corresponding step in the previous exercise.
DDL Source S4D430_BOOKING
@AbapCatalog.sqlViewName: 'S4D430_BOOK'
@AbapCatalog.compiler.compareFilter: true
@AccessControl.authorizationCheck: #CHECK
@EndUserText.label: 'Solution: Flight Booking w Calculations'
define view S4D430_Booking
as select
from sbook as b
{ key b.carrid,
key b.connid,
key b.fldate,
key b.bookid,
case b.class
when 'Y' then 'Economy'
when 'C' then 'Business'
when 'F' then 'First'
else '???'
end as class,
currency_conversion( amount =>
b.forcuram,
source_currency =>
b.forcurkey,
round => 'X',
target_currency =>
cast( 'USD' as abap.cuky),
exchange_rate_type => 'M',
exchange_rate_date =>
b.order_date,
error_handling =>
'SET_TO_NULL' )
as amount
@<Semantics.amount.currencyCode:'CURRENCY',
cast('USD' as abap.cuky) as currency
@<Semantics.currencyCode: true,
b.luggweight
@<Semantics.amount.currencyCode: 'WUNIT',
b.wunit
@<Semantics.currencyCode: true,
b.order_date,
dats_days_between(b.order_date, b.fldate) as
days_ahead,
b.agencynum,
b.counter,
b.customid
}
where cancelled <> 'X'
Define a CDS View that returns only the customer-related information
In this exercise you want to define a new CDS View that returns only the customer-related
information from your solution of the previous exercise (DDL Source Z##_FUNCTIONS). If
you did not complete the previous exercise you can copy from DDL Source
S4D430_FUNCTIONS.
1. In your own package, create a new DDL Source (suggested name: Z##_CUSTOMER,
where ## stands for your group number) based on template defineView.
a) See the corresponding step in the previous exercise.
2. In the new DDL Source, provide a suitable name for the DB View (suggested name:
Z##CUST).
a) See source code extract from the model solution.
112
© Copyright. All rights reserved.
Lesson: Understanding Nested Views
3. In the FROM clause of the SELECT statement specify database table SCUSTOM as data
source.
a) See source code extract from the model solution.
4. Open DDL Source Z##_FUNCTIONS (or DDL Source S4D430_FUNCTIONS) and copy the
field list to the new DDL Source.
a) See the corresponding step in the previous exercise.
5. Remove everything from the field list, that is based on SBOOK.
Hint:
If you specify an alias for table SCUSTOM you can leave the rest of field list
unchanged.
a) See source code extract from the model solution.
6. Activate the DDL Source.
a) See the corresponding step in the previous exercise.
DDL Source S4D430_CUSTOMER
@AbapCatalog.sqlViewName: 'S4D430_CUST'
@AbapCatalog.compiler.compareFilter: true
@AccessControl.authorizationCheck: #CHECK
@EndUserText.label: 'Solution: Flight Customer w Calculations'
define view s4d430_Customer
as select
from scustom as c
{ key c.id,
concat_with_space(c.form, c.name, 1) as
name,
// concat(concat( c.form, ' '), c.name) as
name, // Workaround in 7.40
c.street,
c.postcode,
c.city,
c.country,
@EndUserText.label: 'Discount Factor'
@EndUserText.quickInfo: 'Customer Specific
Discount Factor'
division(cast(c.discount as abap.int4), 100,
2) as discount
}
Define a CDS View that combines data from the two CDS Views
You now want to define a new CDS View that returns exactly the same information as your
solution of the previous exercise (DDL Source Z##_FUNCTIONS). But instead of reading from
the database tables directly and doing the calculations itself, the new CDS View will read from
two other CDS Views that encapsulate the calculations.
1. In your own Package, create a new DDL Source (suggested name:
Z##_BOOKING_AND_CUSTOMER, where ## stands for your group number) based on
template defineView.
a) See the corresponding step in the previous exercise.
2. In the new DDL Source, provide a suitable name for the DB View (suggested name:
Z##BOOKCUST).
a) See source code extract from the model solution.
© Copyright. All rights reserved.
113
Unit 3: More SQL Features in CDS Views
3. Open the DDL Source Z##_FUNCTIONS (or DDL Source S4D430_FUNCTIONS) and copy
the FROM clause, the field list and the WHERE clause to the new DDL Source.
a) See the corresponding step in the previous exercise.
4. In the new DDL Source, edit the FROM clause. Replace tables SBOOK and SCUSTOM with
the two CDS Views you created earlier in this exercise (Z##_Booking and
Z##_Customer).
a) See source code extract from the model solution.
5. Edit the field list. Remove all components with expressions and functions and replace
them with the corresponding fields of the CDS Views.
Note:
If you copied the WHERE clause, too, don’t forget to remove it. It is superfluous
in Z##_Booking_And_Customer as it is already contained in CDS View
Z##_Booking.
a) See source code extract from the model solution.
DDL Source S4D430_BOOKING_AND_CUSTOMER
@AbapCatalog.sqlViewName: 'S4D430_BOOKCUST'
@AbapCatalog.compiler.compareFilter: true
@AccessControl.authorizationCheck: #CHECK
@EndUserText.label: 'Solution: Join of Booking and Customer'
define view S4d430_Booking_And_Customer as select
from S4D430_Booking as b
inner join s4d430_customer as c
on b.customid = c.id
{
key b.carrid,
key b.connid,
key b.fldate,
key b.bookid,
b.customid,
b.amount,
b.currency,
b.days_ahead,
c.name,
c.street,
c.postcode,
c.city,
c.country
}
Activate and Test
1. Activate the DDL Sources.
a) See the corresponding step in the previous exercise.
2. Open the Data Preview for CDS View S4D430_BOOKING_AND_CUSTOMER and ensure
that the displayed data are correct.
a) See the corresponding step in the previous exercise.
114
© Copyright. All rights reserved.
Lesson: Understanding Nested Views
LESSON SUMMARY
You should now be able to:
●
Define CDS Views Based on Other CDS Views
© Copyright. All rights reserved.
115
Unit 3
Lesson 4
Using Aggregations in CDS Views
LESSON OBJECTIVES
After completing this lesson, you will be able to:
●
Use Aggregate Functions, Group By And Having in CDS Views
Aggregate Expressions
Aggregate Functions
Operand can be
a field of the data source
MIN( operand) a.nd MAXi( operand)
- Returns the smallest/greatest value in operand
a literal
a case distinction
SUM( operand)
- Calculates the sum of lhe values or operand
• AVG( oper:and)
- Calculates the average value of the values of operand
• COUNT(")
- Returns the number of entries in the resu It set
• COUNT( DISTINCT operand)
- Returns the number of distinct values of operand
Figure 79: Aggregate Functions
An aggregate expression calculates a single value from an operand (operand) by calling an
aggregate function for multiple rows of a results set. The figure above shows the possible
aggregate functions.
Aggregate expressions can be used in the field list of a SELECT statement or in an (optional)
HAVING clause.
Note:
For aggregate functions in the field list, it is mandatory to provide an alias
(addition AS).
Regarding the result type, the following rules apply:
●
116
The result type of expression AVG is type FLTP.
© Copyright. All rights reserved.
Lesson: Using Aggregations in CDS Views
●
Expressions COUNT and COUNT( DISTINCT …) return an integer value.
●
Expressions MIN, MAX, and SUM have the same result type as operand.
Usually, operand is a column or field in the data source of the current CDS View. Other
options for operand are:
●
Literals
●
Case distinctions
@Abap(atalog. sql ViewName:
'S4D430AGGREGATE '
define view S4d430_Aggregates as select
from sflight
Alias name mandatory
for aggregate expressions
{
count(*)
as c,ol_count,
count(distinct planetype) as col_cnt-dist,
sumi( seatsocc )
as ,c,ol_sum1;
avg ( seatsocc )
as col_avg,
max( seatsocc)
as c,ol_max,
min( seatsocc )
as col_min
as ce l_li te ral.1
sum( 1 )
sumi( case
11,1hen seatsocc > seatsmax then 1
else 0
Sum of literal 1
(Same result as count( *) )
I
Sum of a case distinction
(Count overbooked flights)
end
)
as col_overbooked
}
Figure 80: Example: Aggregate Functions
The example above shows one example for each aggregate function.
The last two elements of the field list are examples of alternative operands.
l@Aba pCatalog. sql ViewName:
'S4D430_AGGRGRP1'
define view S4D430_Aggregat,es_Group_By_l as select
from sflight
{
car rid,
conn id,
count(*)
avg( seatsocc
as col_count,
as col_avg,
}
I group by carrid,
Field list consists not only
of aggregate expressions
I
GOUP BY is need for all
fields in the field list
con1nid
I @Abapcatalog. sqlViewName:
'54D430_AGGRGRP2'
define view $4D430_Aggregat:,es_Group_By_2 as select
from sflight:
{
concart_w.ith_space(ca1rrid" cennfd, 1) as ID,
count(*)
as col_count,
as col_avg,
avg( seat sncc )
group by carrid;, connid
1
Field list contans
expression or function
l
Arguments of the
expression or function
listed individually
Figure 81: Example: Aggregate Functions with GROUP BY
© Copyright. All rights reserved.
117
Addition GROUP BY groups those rows in the result set that have the same content in the
elements specified by the fields field1, field2, ... as a single row. The fields must be specified
using the same names as the fields in the data source.
Any elements of the CDS view that are not specified after GROUP BY must be defined in the
SELECT list using aggregate expressions. Conversely, GROUP BY must be used if aggregate
expressions are contained in the SELECT list and all elements not defined using aggregate
expressions must be specified after GROUP BY. Literals and other expressions cannot be
specified after GROUP BY. If expressions or calls of predefined functions are specified as
elements of the SELECT list using aggregate expressions, all the fields used must be specified
in the GROUP BY clause.
Hint:
The ABAP DDL Source Editor is able to generate the correct GROUP BY clause
automatically from the element list of the view. You can use this feature as
follows:
●
Go to the Problemstab below the editor.
●
Expand node Errors.
●
Right-click error message GROUP BY clause is missing and choose Quick Fix.
●
On the following dialog window, choose Finish.
ERROR: stackunderflow
OFFENDING COMMAND: ~
STACK:
Unit 3: More SQL Features in CDS Views
120
© Copyright. All rights reserved.
Unit 3
Exercise 9
Define a CDS View with Aggregation
Business Example
Template:
Solution:
S4D430_CUSTOMER_WITH_REVENUE (DDL Source)
Create a New DDL Source
1. In your own Package, create a new DDL Source (suggested name:
Z##_CUSTOMER_WITH_REVENUE, where ## stands for your group number) based on
template defineView.
2. In the new DDL Source, provide a suitable name for the DB View (suggested name:
Z##CUSTREV).
Let the New View Read Data from Z##_Booking_And_Customer
1. In the new DDL Source, edit the FROM clause. Make the new CDS View read data from the
CDS View you created in the previous exercise (Z##_Booking_And_Customer). If you did
not complete the previous exercise, you can read from CDS View
S4D430_Booking_And_Customer instead.
2. Edit the field list. Add field CUSTOMID as key field and provide an alias name ID.
3. Add name and address data of the customer (name, street, postcode, city, country).
Add Aggregations and a GROUP BY clause
1. Edit the field list. Add a sum over the converted amount. Specify an alias name
( suggested value: amount) for the sum.
2. After the sum, add the corresponding currency code.
3. Add the required semantics annotation to link the sum to the field with the currency code.
Why is it not necessary to denote field CURRENCY as currency field?
4. Add the average over field DAYS_AHEAD (i.e. the number of days between booking date
and flight date). Specify an alias name (suggested value: days_ahead) for this average.
© Copyright. All rights reserved.
121
Unit 3: More SQL Features in CDS Views
5. Add a GROUP BY clause that lists all fields from the field list that are not aggregate
functions.
Hint:
You can use the Quick Fix for the respective error message to let the editor
insert the correct GROUP BY clause.
Activate and Test
1. Activate the new DDL Source.
2. Open the Data Preview for the CDS View and ensure that the displayed data are correct.
122
© Copyright. All rights reserved.
Unit 3
Solution 9
Define a CDS View with Aggregation
Business Example
Template:
Solution:
S4D430_CUSTOMER_WITH_REVENUE (DDL Source)
Create a New DDL Source
1. In your own Package, create a new DDL Source (suggested name:
Z##_CUSTOMER_WITH_REVENUE, where ## stands for your group number) based on
template defineView.
a) See the corresponding step in the previous exercise.
2. In the new DDL Source, provide a suitable name for the DB View (suggested name:
Z##CUSTREV).
a) See source code extract from the model solution.
Let the New View Read Data from Z##_Booking_And_Customer
1. In the new DDL Source, edit the FROM clause. Make the new CDS View read data from the
CDS View you created in the previous exercise (Z##_Booking_And_Customer). If you did
not complete the previous exercise, you can read from CDS View
S4D430_Booking_And_Customer instead.
a) See source code extract from the model solution.
2. Edit the field list. Add field CUSTOMID as key field and provide an alias name ID.
a) See source code extract from the model solution.
3. Add name and address data of the customer (name, street, postcode, city, country).
a) See source code extract from the model solution.
Add Aggregations and a GROUP BY clause
1. Edit the field list. Add a sum over the converted amount. Specify an alias name
( suggested value: amount) for the sum.
a) See source code extract from the model solution.
2. After the sum, add the corresponding currency code.
a) See source code extract from the model solution.
3. Add the required semantics annotation to link the sum to the field with the currency code.
a) See source code extract from the model solution.
© Copyright. All rights reserved.
123
Unit 3: More SQL Features in CDS Views
Why is it not necessary to denote field CURRENCY as currency field?
Annotation @Semantics.currencyCode: true is inherited from the source CDS View.
4. Add the average over field DAYS_AHEAD (i.e. the number of days between booking date
and flight date). Specify an alias name (suggested value: days_ahead) for this average.
a) See source code extract from the model solution.
5. Add a GROUP BY clause that lists all fields from the field list that are not aggregate
functions.
Hint:
You can use the Quick Fix for the respective error message to let the editor
insert the correct GROUP BY clause.
a) See source code extract from the model solution.
Activate and Test
1. Activate the new DDL Source.
a) See the corresponding step in the previous exercise.
2. Open the Data Preview for the CDS View and ensure that the displayed data are correct.
a) See the corresponding step in the previous exercise.
DDL Source S4D430_CUSTOMER_WITH_REVENUE
@AbapCatalog.sqlViewName: 'S4D430_CUSTREV'
@AbapCatalog.compiler.compareFilter: true
@AccessControl.authorizationCheck: #CHECK
@EndUserText.label: 'Solution: Customer w Aggregated Values'
define view S4d430_Customer_With_Revenue as select
from S4d430_Booking_And_Customer as c
{
key c.customid as id,
c.name,
c.street,
c.postcode,
c.city,
c.country,
sum(c.amount) as amount @<Semantics.amount.currencyCode:
'currency',
c.currency, //@<Semantics.currencyCode: true,
avg(c.days_ahead) as days_ahead
}
group by
c.customid,
c.name,
c.postcode,
c.street,
c.city,
c.country,
c.currency
124
© Copyright. All rights reserved.
Lesson: Using Aggregations in CDS Views
LESSON SUMMARY
You should now be able to:
●
Use Aggregate Functions, Group By And Having in CDS Views
© Copyright. All rights reserved.
125
Unit 3
Lesson 5
Using Additional Join Types and UNION (ALL)
LESSON OBJECTIVES
After completing this lesson, you will be able to:
●
Understand Additional Join Types
●
Understand UNION and UNION ALL
Outer Joins
SQL supports a large variety of join types. Only Inner Joins are supported in classical
database views in ABAP Dictionary.
L
2
3
4
5
x
3
4
5
Figure 83: Reminder: Inner Join
As a reminder, the picture above illustrates an inner join: One row of the left table and one row
of the right table are combined to a common result row if they fulfill the JOIN condition.
126
© Copyright. All rights reserved.
Lesson: Using Additional Join Types and UNION (ALL)
• Left Outer Join
- Special treatment for left table
- Resu It set may contain entries of left table without matching entries in right table
- Supported in classical Open SOL
Right Outer Join
Special treatment for right table
- Result set may contain entries of right table without matching entries in left table
- Supported in Open SQL (as off NW 7.40 SP05) and ABAP CDS
Full Outer Join
- Special treatment for both tables
- Resu It set may contain entries of left table without matching entries in right table
- Result set may contain entries of right table without matching entries in left table
- Not yet supported in Open SQL and ABAP CDS
I
•
Figure 84: Types of Outer Joins
SQL standard knows three (sub)types of outer joins.
L
x
2
NULL
NULL
NULL
NULL
3
4
5
Figure 85: Left Outer Join
In a left outer join, one row of the left table and one row of the right table are combined to a
common result row if they fulfill the JOIN condition (like in inner joins).
In addition, rows of the left table without matching row in the right table are copied to the
query result. The missing values (from the right table) are filled with NULL values.
A left outer join ensures that any entry of the left table that fulfills the selection criteria
appears at least once in the join result.
© Copyright. All rights reserved.
127
Unit 3: More SQL Features in CDS Views
Note:
These NULL values are set to a type-friendly initial value when the CDS view is
used in Open SQL.
NULL
L
2
3
4
5
x
3
4
5
6
NULL
NULL
7
NULL
NULL
Figure 86: Right Outer Join
In a right outer join the role of left and right table are exchanged:
Rows of the right table without matching row in the left table are copied to the query result.
The missing values (from the left table) are filled with NULL values.
A right outer join ensures that any entry of the right table that fulfills the selection criteria
appears at least once in the join result.
128
© Copyright. All rights reserved.
Lesson: Using Additional Join Types and UNION (ALL)
NULL
L
2
3
4
5
x
11
NULL
NULL
2
NULL
NULL
3
4
5
6
7
NULL
NULL
NULL
NULL
Figure 87: Full Outer Join (not supported in ABAP CDS)
In a full outer join, both tables are treated in the same way.
Rows of both tables without matching row in the other table are copied to the query result.
The missing values (from the other table) are filled with NULL values.
I»
Note:
Full outer joins are not yet supported in Open SQL or ABAP CDS. As a work
around, you can use a UNION (see later) of a left outer join and a right outer join.
@AbapCatalog. sql ViewNlarne; 'S4D430_JOINRIGHT'
define view S4d430_Join_Right_outer as select
from spfli as c: right outer join sc:arr as a
on c.carrid = a.carrid
key a.carrid,
a.carrname,
c.connid,
c. ci ty+r-on,
c.cityto
}
cemd
coanid
No flight connections in
table SPFLI for Carriers
"AB", "AC" and "AF"
<il)d,oo,
0011
N�IYOAA
.Amerian.Air1inM
0064
Sl>INFIIANDSCO
N[WYORK
Air8e,t;a
0000
0000
0000
O�S'i
RO E
fRANl(flU.Rf
Amtri<1r1Airli es
A,,C,nJdo
AirfrfllCC
Alitllla
Figure 88: Example: Right Outer Join
© Copyright. All rights reserved.
129
Unit 3: More SQL Features in CDS Views
The figure gives you an example of a CDS View with a right outer join. The Data Preview for
this CDS View clearly shows the entries from the right table (SCARR) without matching
entries in the left table (SPFLI).
Cross Join
I L
x
I
y
3
4
--------
2
3
R
5
�--,--............,,__.......,,,.....�IN Co�
x
y
3
4
2
2
2
3
3
3
5
3
4
5
3
4
5
Figure 89: Cross Join (As off Release 7.51)
When two data sources are joined using CROSS JOIN, the result is the cross product of these
two data source: All entries on the left side are combined with all entries on the right side. The
number of rows in the results set is the number of rows on the left side multiplied by the
number of rows on the right side. It is not possible to specify a join condition for cross joins.
Note:
A cross join behaves like an inner or outer join whose ON condition is always true.
A cross join with a WHERE condition has the same result as an inner join with an
identical ON condition. Unlike the inner join, in a cross join all data is read first
before the condition is evaluated. In an inner join only data that meets
the ON condition is read.
130
© Copyright. All rights reserved.
Lesson: Using Additional Join Types and UNION (ALL)
l@AbapCatalog.sqlViewName; 'S4D430_JOINCROSS'
define view S4D430 JOIN CROSS as select
from
spfli-as cjcr,oss jo.1nl scal"r as a
k.eyja.carr1a1as carrid_scarr,
a.carrname.,
jc. ca rl"id jas cal"rid_spfli,
c.connidi�
c. ci tyfrom.,
c.cityto
I}
.:ii
100 row, retrieved • 3 rm ,��1 resuh)
<!'1\id_�fli
sa
om
AmfflunAirlin6
RO Ml
<ilyfron,
<rl,10
FAANl':l'UftT
rn
i';Wl
FMN!J'UITT
8ERllN
AmMunAillin�
UA
@all
FA:AN!J'UITT
SANFIUlN ...
Ame,i.:.anA.iflinitS
A?.
ll-l
Of
om
�
TOKYO
F�IIJ'UITT
ROMt
NfWVOIII:
0005
SING,11.PORE
fAANKl'Ultf
Amc,ionAirtln�
Amak•n Ailline>
l
itonnid
AmittlunAirtlnH
Figure 90: Example: Cross Join
• All Data Is Read
- No preseleclion through a join condition
Exception: If both tables are client specific an implicit join condition for the client
field is used
• Large Data Sources-· Huge Result Set
- Number or results is always the product or the number of all r(W{S of both data
sources
Figure 91: Warnings Regarding Cross Join
Caution:
A cross join should only be used with extreme caution. Since it is not possible to
specify an ON condition, all data of all involved data sources is read. In the case
of very large datasets, the results set (whose number of rows is always the
product of the number of all rows of both data sources) can quickly become very
large.
Multiple Joins
• Explicit (with parantheses) or Implicit (no pa.rantheses)
- Parentheses are recommended (makes the code easier to read)
• Implicit Order of Evaluation
INNER and OUTER JOINS: Arrangement of the ON conditions
- CROSS JOINS from left to right
Figure 92: Nested Join Expressions – Order of Evaluation
© Copyright. All rights reserved.
131
Unit 3: More SQL Features in CDS Views
The FROM clause of a CDS View definition allows nested join expressions.
You can use parentheses (brackets) in order to influence the sequence in which the system
evaluates these nested expressions.
Note:
The use of parentheses is recommended for making the code easier to read and to
avoid unexpected behavior.
Without parentheses, nested join expressions are evaluated in the following order:
●
●
In the case of inner and outer joins, by the arrangement of the ON conditions. From left to
right, the most adjacent ON conditions are assigned to each JOIN and this expression is
parenthesized implicitly.
Cross joins are evaluated from left to right.
Note:
If several cross joins are combined, the order of the evaluation is irrelevant. The
result is always the same and the number of rows is the product of the number of
rows of all involved data sources. If cross joins are combined with inner and outer
joins, the result can depend on the order of evaluation or the parentheses.
Ill
@Abap(atalog. sql ViewNlame: 'S4D430_JOINNEST'
Join in parentheses
is evaluated first
define view S4d430_Join_Nested as select
from scarr as a
left outer join (
sairport asp
left outer join scounter as c
on p.id
on a.carrid
a. carrid
=
c.airport
c.carrid
as carrier_id,
p.id
as airport_id,
c.countnum as counter_number
}
Figure 93: Example: Nested Join Expression
This example reads information about ticket counters (table scounter). This information is
joined with details about the airport where the ticket counter is located (table sairport) and
the carrier which runs the counter (table scarr).
The example uses outer joins because the result set should also include airports, where there
are no ticket counters, and carriers, that do not run any ticket counters at all.
The parentheses are not required. But they are used to increase the readability of the
expression.
132
© Copyright. All rights reserved.
Lesson: Using Additional Join Types and UNION (ALL)
I
@Abap(atalog. sqlViewNlame; 'S4D430_JOINIMPL'
define view S4d430_Join_Nested_Implicite as select
from scarr as a
left outer join sairport asp
left outer join scounter as c:
on p.id = c.airport
on a.carrid = c.carrid
a. carrid
No parantheses:
Sequence of
ON-conditions rules
as carrier_id,
p.id
as airport_id,
c:.countnum as counter_number
}
l
Figure 94: Example: Same Join with Implicite Ordering
The figure above shows the same nested join expression, but this time without parentheses.
This has no influence on the result. The two joins are evaluated in exactly the same order.
But even for experienced developers, the evaluation order will not be obvious at first glance.
Note:
When defining views with nested joins, always add the parentheses to improve
readability.
Prerequisites and Result Set of UNION
SELECT A, Bj C, D
FROM ... WHIERE
u, •
B
c
o
2
2
3
4
3
4
2
3
4
2
3
4
A
A
B
c
D
1
1
2
2
3
1
2
1
2
3
4
2
UNION
3
SELECT A, B., x as
FROM ... WHERE ...
A
2
3
4
B
2
3
4
x
2
3
4
y
.2
Duplicates are removed
from the result set
3
4
Figure 95: UNION
If you place keyword UNION ALL between two select statements, you create the union of rows
in the two results sets. Completely identical entries are removed from the result set.
A union results set can itself be the left side of a further union.
© Copyright. All rights reserved.
133
Unit 3: More SQL Features in CDS Views
Prerequisites
Compatible Structure of Result. Sets
- Same number of eleDlents
- Elements in same position have coml)atlble data type
- Elements in same position have identical name/alias
Properties of Result SET
• Element Names
- Are (identical) in both original resu It sets and are taken from there
Key Definition
- taken from first SELECT statement
Element Type
- ABAP Dictionary ty-pe with sufficient value range
I
Figure 96: UNION: Prerequisites and Result Set
A prerequisite for UNION (ALL) is that the structures of the results sets are compatible. This
means that the results sets must have the same number of elements and that the pairs of
elements in each position have a compatible data type. The element names of the result sets
must match.
The properties of the union results set are defined as follows:
●
●
●
The element names are taken either from an explicitly specified name list or, if no list is
specified, the matching names from the SELECT lists of all SELECT statements are used.
The definition of the key elements is taken from the SELECT list of the first SELECT
statement.
The data type of each element is a data type from ABAP Dictionary whose value range
covers the data types of the associated columns of all results sets involved.
@Abap(atalog .. s ql ViewNlame:
'S4D430_ UNIIO'
define view S4d430_Union as
select from scustom
{
Ikey id,
Ikey 'Customer'
as type)
name,
city,
country
Key defin1itiion in second
select is ignored
r
}
union
select from stravelag
{
�ey agencynum
'Agency
name,
city,
country
as id,
as type,
Alias id is needed to have
identical element names
l
Additional blanks needed
to have compatible types
Figure 97: Example: UNION
134
© Copyright. All rights reserved.
Lesson: Using Additional Join Types and UNION (ALL)
The CDS view in this example reads flight customers from table SCUSTOM and travel
agencies from table STRAVELAG. The two result sets are merged into one by using key word
UNION.
A field with name TYPE is filled with literal 'Customer' or 'Agency ' to make the rows in the
result set distinguishable. This field is a key field of the resulting view because it is labelled
with "key" in the first select.
Note:
The two literals have to be of identical length to fulfill the requirement, that
corresponding elements need compatible types!
Difference between UNION and UNION ALL
Iii
SELECT A, B,. C,. D
FROM ... WHERE ...
A
B
c
D
2
3
4
2
3
4
2
3
4
2
3
4
UNION ALL
SELECT A, B, X as C, Y as ID
FROM .... WH'ERE ....
A
2
3
4
B
2
3
4
x
y
2
3
2
3
4
4
c
D
1
4
1
2
3
4
2
3
4
2
3
4
3
B
1
2
3
I
3
4
4
I
2
3
4
3
4
A
1
.2
2
2
I
I
Figure 98: UNION ALL
If the addition ALL is not specified, all duplicate entries are removed from the results set. They
are not removed if ALL is specified.
© Copyright. All rights reserved.
135
Unit 3: More SQL Features in CDS Views
@Aba peat a log. sql ViewName: • 54D430_UNIOAL Ll"
define view S4d4l3,0_Urnion_All_l as
select from scustom
{ key id }
where city� 'Walldorf'
u-n�i no -a·�1""';1 ..j
,.
j
select from sbook
{ key c:ustomid as id }
wlh,ere agencynum = '00000100'
L
f;ba
peat a log. sql ViewName:
'54!D430_UNIOAL L2"
define view S4dU0_Ut11ioJl_Al1_2 as
select from scustom
{ key i.d }
where city = 'Walldorf'
jun1on
I select
L
I
from sbook
{ key customid as id}
where aeencynum = ·00000100'
•
l•
Same definition
without ALL
L
id
....
00000001
!ooooooo1
00000002
00000003
ooooooos
OOOCil0006
R�w�
--;
id
00000001
00000002
00000003
00000005
00000006
Figure 99: Example: UNION vs UNION ALL
The CDS views in this example read customer ids from table SCUSTOM (Customers with
address in 'Walldorf') and from table SBOOK (customers that booked with travel agency
'00000100').
In the first data definition key word UNION ALL is used. The second CDS view reads exactly
the same data but uses UNION without addition ALL.
Customer '00000001' has an address in Walldorf and made one booking with travel agency
'00000100'. Consequently, the result set of the first CDS View contains customer ID
'00000001' twice. With keyword 'UNION' instead of 'UNION ALL' the second entry is removed
from the result set.
Advantages of UNION (ALL)
136
© Copyright. All rights reserved.
Unit 3
Exercise 10
Define a CDS View with a UNION statement
Business Example
Template:
Solution:
S4D430_PARTNER_WITH_REVENUE (DDL Source)
Create a New DDL Source
1. In your own Package, create a new DDL Source (suggested name:
Z##_PARTNER_WITH_REVENUE, where ## stands for your group number) based on
template defineView.
2. In the new DDL Source, provide a suitable name for the DB View (suggested name:
Z##PARTREV).
Select Customers with Revenues
Implement a first SELECT statement to read customers with revenue
1. In the new DDL Source, edit the FROM clause. Implement a select from your CDS View
Z##_Customer_With_Revenue. If you did not complete the previous exercise, you can
read from CDS View S4D430_Customer_With_Revenue, instead.
2. Edit the field list. Add field id as key field.
3. Add all other fields from the basis view, i.e. name and address data, total amount with
currency and field DAYS_AHEAD.
Implement a UNION statement
Add a SELECT statement to read travel agencies with revenue.
1. After the first SELECT statement, at the very end of your DDL Source, type another
SELECT statement to read from CDS View S4D430_Agency_With_Revenue.
2. Select the same fields (in the same order!) as in the first SELECT.
3. Link the two SELECT statements with keyword UNION to have the two result sets
combined on the database level.
Add a Field for the Partner Type
Add a field that helps to distinguish flight customers from travel agencies.
1. Edit the field list of the first SELECT statement. Add a literal ‘C’ (for Customer) between
fields ID and NAME.
2. Provide an alias for the literal (suggested alias: type).
© Copyright. All rights reserved.
137
Unit 3: More SQL Features in CDS Views
3. Edit the field list of the second SELECT statement. This time, add literal ‘A’ (for Agency).
Note:
Make sure that in both SELECT statements the literal has the same position in
the field list and alias name.
Activate and Test
1. Activate the new DDL Source.
2. Open the Data Preview for the CDS View and ensure that the displayed data are correct.
138
© Copyright. All rights reserved.
Unit 3
Solution 10
Define a CDS View with a UNION statement
Business Example
Template:
Solution:
S4D430_PARTNER_WITH_REVENUE (DDL Source)
Create a New DDL Source
1. In your own Package, create a new DDL Source (suggested name:
Z##_PARTNER_WITH_REVENUE, where ## stands for your group number) based on
template defineView.
a) See the corresponding step in the previous exercise.
2. In the new DDL Source, provide a suitable name for the DB View (suggested name:
Z##PARTREV).
a) See source code extract from the model solution.
Select Customers with Revenues
Implement a first SELECT statement to read customers with revenue
1. In the new DDL Source, edit the FROM clause. Implement a select from your CDS View
Z##_Customer_With_Revenue. If you did not complete the previous exercise, you can
read from CDS View S4D430_Customer_With_Revenue, instead.
a) See source code extract from the model solution.
2. Edit the field list. Add field id as key field.
a) See source code extract from the model solution.
3. Add all other fields from the basis view, i.e. name and address data, total amount with
currency and field DAYS_AHEAD.
a) See source code extract from the model solution.
Implement a UNION statement
Add a SELECT statement to read travel agencies with revenue.
1. After the first SELECT statement, at the very end of your DDL Source, type another
SELECT statement to read from CDS View S4D430_Agency_With_Revenue.
a) See source code extract from the model solution.
2. Select the same fields (in the same order!) as in the first SELECT.
a) See source code extract from the model solution.
© Copyright. All rights reserved.
139
Unit 3: More SQL Features in CDS Views
3. Link the two SELECT statements with keyword UNION to have the two result sets
combined on the database level.
a) See source code extract from the model solution.
Add a Field for the Partner Type
Add a field that helps to distinguish flight customers from travel agencies.
1. Edit the field list of the first SELECT statement. Add a literal ‘C’ (for Customer) between
fields ID and NAME.
a) See source code extract from the model solution.
2. Provide an alias for the literal (suggested alias: type).
a) See source code extract from the model solution.
3. Edit the field list of the second SELECT statement. This time, add literal ‘A’ (for Agency).
Note:
Make sure that in both SELECT statements the literal has the same position in
the field list and alias name.
a) See source code extract from the model solution.
Activate and Test
1. Activate the new DDL Source.
a) See the corresponding step in the previous exercise.
2. Open the Data Preview for the CDS View and ensure that the displayed data are correct.
a) See the corresponding step in the previous exercise.
DDL Source S4D430_PARTNER_WITH_REVENUE
@AbapCatalog.sqlViewName: 'S4D430PARTREV'
@AbapCatalog.compiler.compareFilter: true
@AccessControl.authorizationCheck: #CHECK
@EndUserText.label: 'Solution: Union of Customers & Agencies'
define view S4D430_Partner_With_Revenue as
select
from S4d430_Customer_With_Revenue
{
key id,
'C' as type,
name,
street,
city,
country,
amount,
currency,
days_ahead
}
union
select
from S4d430_Agency_With_Revenue
{
key id,
140
© Copyright. All rights reserved.
Lesson: Using Additional Join Types and UNION (ALL)
'A' as type,
name,
street,
city,
country,
amount,
currency,
days_ahead
}
© Copyright. All rights reserved.
141
Unit 3: More SQL Features in CDS Views
LESSON SUMMARY
You should now be able to:
142
●
Understand Additional Join Types
●
Understand UNION and UNION ALL
© Copyright. All rights reserved.
UNIT 4
Advanced Concepts
Lesson 1
Defining CDS Views with Input Parameters
Exercise 11: Define and Use a CDS View with Input Parameter
145
153
Lesson 2
Building CDS Views with Associations
Exercise 12: Define a CDS View with Associations
Exercise 13: Use a CDS View with Associations
161
169
181
Lesson 3
Enhancing a CDS View
Exercise 14: Enhance a CDS View
188
197
Lesson 4
Linking a CDS View with Authorization Rules
Exercise 15: Create and Use a DCL Source
203
213
UNIT OBJECTIVES
●
Define CDS Views with Input Parameters
●
Provide Values for Input Parameters of a CDS View
●
Specify a Default Value for an Input Parameter
●
Define Views with Associations
●
Expose Associations
●
Use Exposed Associations in Path Expressions
●
Understand Filtered Associations
●
Understand the Concept of CDS View Enhancements
●
Enhance a CDS View
●
Understand the Concept of CDS DCL
© Copyright. All rights reserved.
143
Unit 4: Advanced Concepts
●
144
Create a DCL Source
© Copyright. All rights reserved.
Unit 4
Lesson 1
Defining CDS Views with Input Parameters
LESSON OBJECTIVES
After completing this lesson, you will be able to:
●
Define CDS Views with Input Parameters
●
Provide Values for Input Parameters of a CDS View
●
Specify a Default Value for an Input Parameter
Input Parameter Declaration
In the previous unit we learned how powerful CDS Views are when it comes to making
calculations and pre-processing of the raw data found in database tables.
Examples for·the Need of Input Parameters
• Input for SQL expressions and functions, e.g.
- a discount factor when ca.lculaling a price
- the separation character when concatenating text
- the target currency for a currency conversion
Selection o·f Data. to Enter an Aggregation, e.g.
- date up to which revenue shall enter a summation
Madatory Selection Criteria, e.g.
- language key
- user name
I
Figure 100: Input Parameters in CDS Views
The new possibilities immediately rise the question in how far the consumer of the CDS View
(ABAP program, other CDS View) can influence the way the calculations are done. Of course
the consumer can provide a WHERE clause to make a selection of the results. But how does
that help when you want to specify the target currency for a currency conversion?
CDS Views that contain an aggregation expression are another important example for the
need of input parameters. If, for example, a CDS View calculates the sum of revenues, the
view itself can restrict the revenues that enter the equation. But fields like the booking date
will not be part of the views element list and the consumer of the view will have no chance to
refer to it in his WHERE clause.
Finally, SQL does not know such things as mandatory selection criteria. A consumer may
provide a WHERE clause or might not. With a mandatory input parameter the view can force
the consumer to provide a necessary selection criterion like e.g. a language key or a user
name.
© Copyright. All rights reserved.
145
Unit 4: Advanced Concepts
I @Abapcatalog. sqlViewName:
Addition
"S4D430_PARAM'
WITH PARAMETERS
define view S4d430_Parameter
with parameters
parameteirl: abap. char-(16).,
1
Predefined Dictionaiy
parameter2: s_carr_ id.,
type or data element
l
l
@EndUserlext. label: 'Disc,ou11t'
@EndUserlext. quick Info: 'Discount Fa,ct,or for Price '
factor:
o·bap.dec(3., 2),
EndUserT ext-Annotations
separator: abap.char(l)
before the parameter ..
@< EndUserText. label: 'Separation Character'
as select
from sflight
L:
... or after the parameter
Figure 101: Example: View Definition with Input Parameters
You define input parameters by placing addition WITH PARAMETERS after the CDS View
name. The parameters are then defined in a comma-separated list.
Each input parameter must be typed with an elementary data type. This can be a predefined
ABAP Dictionary type (in the form abap.<type>(<len>) ), or a data element. Structure types,
table types or reference types are not allowed.
You can use annotations to provide additional information for parameters. Annotations Like
annotations in the element list, annotations in the parameter list can be specified before the
parameter or after the parameter.
Template defineViewWithParameters
x
0
NcwO�tD Ddinitio,i
Templa.te·s
I
Select eae C>f the avait�ble temp1�t.e:..
0, U,e Un� •elected lempl•le
@lDelim.e�ew
@1De me1/i....,wlthJl>i:ri
Dtlii\e__�ewwith A��o<iati,on__
D.tin .. • vlowwith • .ingl• input psremeter,
The input
pam11ete1 ca" be u� .u �n e!9'1"19't in �l"le
st!fct lirt •Ot u � n optrancl in tonclilic.nal er� rill1milic
1
e:xpressr:Dns.
Caned
Figure 102: Template "defineViewWithParameter"
146
© Copyright. All rights reserved.
Lesson: Defining CDS Views with Input Parameters
There is a dedicated template for creating a view definition with input parameter.
Access to Input Parameters
@Abapcatalog.sqlViewName: 'S4D430_PARAM'
define view S4d430_Parameter
with parameters
para1meter1: abap. char(10),
para1meter2: s_carr_ id
Prefix.ed with
,.$parameters.''
(recommended}
as select
from sflight
$pa1rameters. parameterl as par-am1,
: parameter.2
as param2;
}
Prefixed with ,.:"
(not recommended)
Figure 103: Example: How to Access Input Parameters
There are two ways to address input parameters: The long version is with prefix
"$parameters.", the short version is a simple colon(":") before the parameter name. It is
recommended to use the long version. Only the long version is supported by source code
completion.
• In the Element List
- as standalone element
• In Expressions
- as operand in an expression
as input for a predefined SQL function
dir-ectly after case in a case distinction
• In the WHERE clause or HAVING clause
- Right side of a condition
• In the ON ,condition of a Join
- Righi side of a condition
Figure 104: Where to Access Input Parameters
You can use an input parameter in the following positions:
●
Element in the SELECT list.
●
Operand of an arithmetic expression.
●
Operand directly after case in a case distinction.
●
Right side of a condition in a WHERE clause or HAVING clause.
© Copyright. All rights reserved.
147
Unit 4: Advanced Concepts
●
Right side of a condition in an ON condition in a join.
Input Parameters in Data Preview
Ill
Cl
Optn widi Dat� Pre.itw
x
IEnter Parome1er Values
Q) Type:cha!(10)
I
!
PAIIAMETER1:" Anythin�
PARAMHER:2:
FACTOR:'
SE!PARATOR.:"
l�L=H====================================================�I
l::0=90==========================�1
.
l._x
__,1
OK
J
�,
Figure 105: Input Parameters in Data Preview
If you open Data Preview for a CDS View with input parameter(s), you are prompted to enter
actual values for all input parameters.
I»
Note:
It is currently not possible to define optional input parameters for CDS views.
Only such entries are accepted that are compatible with the parameter type. But the tool does
not perform any further checks. If, for example, the parameter is typed with a data element
that is based on a domain, the entry is not checked against the allowed fixed values in this
domain.
Hint:
When the focus is on an input field, the screen displays the expected type above
the input mask.
148
© Copyright. All rights reserved.
Lesson: Defining CDS Views with Input Parameters
Input Parameters in CDS DDL
@AbapCatalog. sql ViewNarne; 'S4D430_US EP.ARAM'
CDS View with Parameters
as data source
define view S4d430_Use_Parameters
with parameters
factor : obap .. dee( 3,. 2 )
Parameter passing
1
in parantheses ,,()''
as selec:t
from S4d430_Parameter( parameter!.: 'Any Text',
parameter2: 'LH',
factor:
$parameters.factor,
separator:
'X'
This parameter is
{
,,forwarded"
}
Figure 106: Example: Use Input Parameters in CDS DDL
When a CDS View reads from another CDS view that has input parameters, all these input
parameters have to be supplied with actual values. This is done within parantheses
immediately after the the name of the source view in the FROM clause (see the example
above). No blank is allowed before the opening parenthesis.
Note:
All parameters have to be supplied and they have to be in the same order as in the
definition of the view.
[o
Hint:
If you use the auto-completion capabilities of the editor, you don't have to look
up the names and sequence of the parameters.
You can use the following as actual value for an input parameter:
●
Literal (text or number)
●
An input parameter of your own CDS View ("forwarding" of a parameter)
●
A session variable
© Copyright. All rights reserved.
149
Unit 4: Advanced Concepts
Input Parameters in Open SQL
Assignment with .. ="
instead of .:"
SELECT FROM s4d430_param.eter(
parameterl = @( 'Carrier' && pa_car ),
'0.93',
factor
parameter2
@pa_car,
separator = ·x·
>
FIELDS*
WHERE carrid
=
@pa_car
INTO TABLE @gt_data.
Sequence of parameters
not fixed
Literals, host variables
or host expressions
Figure 107: Example: CDS View With Parameters in Open SQL
In Open SQL, actual parameters for the input parameters of a CDS view are specified in a
parenthesized comma-separated list. The syntax is very similar to that used in CDS DDL.
There are two important differences:
●
●
Open SQL uses assignment operator "=". CDS DDL uses character ":", instead.
The sequence of the parameters does not have to match the sequence in the view
definition.
The following can be used as actual parameters:
150
●
Literals
●
Host variables (of elementary type)
●
Host expressions (with elementary result type)
© Copyright. All rights reserved.
Lesson: Defining CDS Views with Input Parameters
Before Release 7.50:
Input parameters. only supported on SAP HANA database
• Check of system capability needed:
DATA gt_fea.ture_set TYPE cl_abap:.._dbfeatures=>features sett.
I:NSF.RT cl_abap_dbfeatures=>views_with_parameters
INTO TABLE gt_feature_set.
IF cl_abap_dbfeatures=>use_features( gt_fea.ture_set
= abap_false.
END[F.
As of
elease 7
so·
Input parameters supported on all DB platforms
• Syntax above obsolete (warning from syntax check)
l
Figure 108: Restricted support in Release 7.40
Before Release 7.50, CDS views with input parameters were only supported on SAP HANA
database. Reading from them when the system was connected to another database will result
in runtime errors.
To avoid these runtime errors, it is necessary to query property VIEWS_WITH_PARAMETERS
using method USE_FEATURES of class CL_ABAP_DBFEATURES (See sample code above).
With Release 7.50 and higher, the input parameters of CDS views are supported by all
database platforms and can be used in Open SQL. The check mentioned above is no longer
required. Querying this property results in a warning check from the syntax check.
Default Value for Parameters in Open SQL
No actual parameters
in Open SQL SELECT
Internal session
System Fields
ABAP Program
DATUM
SELECT' FROM My_Cds_View
FIELDS
* ....
CDS View {witlh annotated Parameters)
Input Parameters
are supplied
from related
system fields
p_langu ,______�
define view My_Cds_View
with parameters
p_date
syst_datum @<l:nvironment. systemFieLd: #SYSTEM_DA Tl:J
p_langu : syst_Langu @<Environment.systemFieLd; #SYSTEM_LANGUA6E
as select
Figure 109: Optional Parameters for CDS Views
© Copyright. All rights reserved.
151
Unit 4: Advanced Concepts
You learned already that optional parameters are currently not supported in CDS views. In
other words: When you access a CDS View with parameters, you have to provide actual values
for all parameters.
There is one exception from this rule: You can use annotation Environment.systemField to link
an input parameter to a system field of the ABAP runtime environment. Examples of such
system fields are sy-datum for system date or sy-langu for the logon language.
When a CDS View is used as data source in an Open SQL SELECT statement, any parameter
annotated with Environment.systemField is considered optional. If no actual value is supplied,
like in the example above, the system automatically supplies the parameter with the content
of the related system field.
• 5 diffe,rent values
system rield
#CLIENT
sy-mandt
#SYSTEM_DATA
sy-datum
#SYSTEM_ TIME
sy-vzeit
#SYSTEM_LANGUAGE
sy-langu
#USER
sy-uname
• Strictly o:nce per parameter
• Has an ·e·ff,ect only in Open SQL
(when using the view iin another CDS view, the annetanon Is ig1nol'edl)
• Special rulle for #CI..IENT:
Explicit Actual value not allowed
Figure 110: Rules for Annotation Environment.systemField
The list above shows the supported values for annotation Environment.systemField and the
system fields they are related to.
You can use annotation Environment.systemField strictly once per parameter. It is not
supported (and wouldn't make any sense) to link the same parameter to more than one
system field.
Note:
Annotation Environment.systemField only has an effect in Open SQL. When you
use the CDS View in another CDS View, the annotation will be ignored and the
parameter remains mandatory.
If a parameter is annotated with Environment.systemField, you can either make use of the
default value from the system field or "override" that value with an explicit actual parameter.
There is only one exception:
For parameters annotated with Environment.systemField: #CLIENT, it is forbidden to specify
an actual parameter explicitly. This rule has been introduced to avoid conflicts with Open SQL
addition USE CLIENT.
152
© Copyright. All rights reserved.
Unit 4
Exercise 11
Define and Use a CDS View with Input
Parameter
Business Example
Template:
S4D430_CUSTOMER_WITH_REVENUE (DDL Source)
S4D430_INTRO_S2 (Executable Program)
Solution:
S4D430_CUSTOMER_WITH_PARAMETER (DDL Source)
S4D430_PARAM_S1 (Executable Program)
Define a CDS View with Input Parameter
Create a copy of your CDS View for Customers with Revenue and extend it with an input
parameter that allows the user to specify a date up to which the bookings enter the
calculation.
1. In your own Package, create a new DDL Source (suggested name:
Z##_CUSTOMER_WITH_PARAMETER, where ## stands for your group number) based
on template defineViewWithInputParameters.
2. In the new DDL Source, provide a suitable name for the DB View (suggested name:
Z##CUSTREV2).
3. Provide a meaningful name for the generated input parameter (suggested name: P_) and
type it with the appropriate abap data type for date fields.
Hint:
When in doubt, type abap. and hit Ctrl + Space. Search the offered data
types for one with description Date in Format YYYYMMDD.
4. Open your DDL Source Z##_CUSTOMER_WITH_REVENUE and copy the FROM clause
and the field list to the new DDL Source. If you did not complete the respective exercise,
you can copy from DDL Source S4D430_CUSTOMER_WITH_REVENUE.
5. Edit the new DDL Source (i.e,. the one with the input parameter). Add a WHERE clause to
the SELECT statement and use the input parameter to restrict the selection to flights that
took place before the given date.
6. Activate your new DDL Source and open the data preview for the new CDS View.
Use Input Parameters in Open SQL
Use your CDS View with input parameter in Open SQL and provide a value for the parameter.
© Copyright. All rights reserved.
153
Unit 4: Advanced Concepts
1. Create a copy of your executable program Z##R_OPEN_SQL (suggested name:
Z##R_OPEN_SQL_PARAM, where ## is your group number). If you did not complete the
respective exercise, you can copy executable program S4D430_INTRO_S2, instead.
2. Change the definition of local data type ty_t_customers. Replace line type
S4d430_Customer_With_Revenue with your new CDS View
Z##_Customer_With_Parameter.
3. Change the SELECT statement. In the FROM clause, replace CDS View
S4d430_Customer_With_Revenue with your new CDS View
Z##_Customer_With_Parameter. Supply the CDS View’s input parameter with system
field sy-datum.
4. Activate and test your program.
System Field as Default Value for Input Parameter
Use an annotation to link your input parameter with system field sy-datum.
1. Edit your DDL Source Z##_CUSTOMER_WITH_PARAMETER. Use annotation
@Environment.systemField for the input parameter to use the system date as default
value.
2. Activate the DDL Source and open the data preview for the new CDS View.
Why are you still prompted to enter a value for the input parameter? And why is there no
default value for the parameter?
3. Return to your executable program Z##_PARAM_S1 and perform a syntax check.
Why do you suddenly get a syntax error that requires that you move the INTO clause to
the very end of the SELECT statement?
4. Adjust the SELECT statement according to the new syntax rules of release 7.50: Move the
INTO clause to the very end of the statement.
5. Edit your program Z##_PARAM_S1. Copy the entire SELECT statement. In the copied
SELECT statement, remove the parameter passing (brackets after the name of the CDS
View).
6. Perform a syntax check to verify, that now a parameter passing is not needed anymore.
154
© Copyright. All rights reserved.
Unit 4
Solution 11
Define and Use a CDS View with Input
Parameter
Business Example
Template:
S4D430_CUSTOMER_WITH_REVENUE (DDL Source)
S4D430_INTRO_S2 (Executable Program)
Solution:
S4D430_CUSTOMER_WITH_PARAMETER (DDL Source)
S4D430_PARAM_S1 (Executable Program)
Define a CDS View with Input Parameter
Create a copy of your CDS View for Customers with Revenue and extend it with an input
parameter that allows the user to specify a date up to which the bookings enter the
calculation.
1. In your own Package, create a new DDL Source (suggested name:
Z##_CUSTOMER_WITH_PARAMETER, where ## stands for your group number) based
on template defineViewWithInputParameters.
a) See the corresponding step in the previous exercise.
2. In the new DDL Source, provide a suitable name for the DB View (suggested name:
Z##CUSTREV2).
a) See source code extract from the model solution.
3. Provide a meaningful name for the generated input parameter (suggested name: P_) and
type it with the appropriate abap data type for date fields.
Hint:
When in doubt, type abap. and hit Ctrl + Space. Search the offered data
types for one with description Date in Format YYYYMMDD.
a) See source code extract from the model solution.
4. Open your DDL Source Z##_CUSTOMER_WITH_REVENUE and copy the FROM clause
and the field list to the new DDL Source. If you did not complete the respective exercise,
you can copy from DDL Source S4D430_CUSTOMER_WITH_REVENUE.
a) See the corresponding step in the previous exercise.
© Copyright. All rights reserved.
155
Unit 4: Advanced Concepts
5. Edit the new DDL Source (i.e,. the one with the input parameter). Add a WHERE clause to
the SELECT statement and use the input parameter to restrict the selection to flights that
took place before the given date.
a) WHERE fldate < $Parameters.P_FlightsBefore or WHERE fldate
< :P_FlightsBefore
b) See source code extract from the model solution.
6. Activate your new DDL Source and open the data preview for the new CDS View.
a) See the corresponding step in the previous exercise.
b) When prompted to enter values for parameters, enter a valid date, e.g. today, in
“technical” format YYYYMMDD.
DDL Source S4D430_CUSTOMER_WITH_PARAMETER
@AbapCatalog.sqlViewName: 'S4D430CUSTREV2'
@AbapCatalog.compiler.compareFilter: true
@AccessControl.authorizationCheck: #CHECK
@EndUserText.label: 'Solution: Input Parameter'
define view S4d430_Customer_With_Parameter
with parameters
@EndUserText.label: 'Consider flights up to this date'
P_FlightsBefore : abap.dats
as select
from S4d430_Booking_And_Customer as c
{
key c.customid as id,
c.name,
c.street,
c.postcode,
c.city,
c.country,
sum(c.amount) as amount @<Semantics.amount.currencyCode:
'currency',
c.currency, //<@Semantics.currencyCode: true,
avg(c.days_ahead) as days_ahead
}
where fldate < $parameters.P_FlightsBefore
group by
c.customid,
c.name,
c.postcode,
c.street,
c.city,
c.country,
c.currency
Use Input Parameters in Open SQL
Use your CDS View with input parameter in Open SQL and provide a value for the parameter.
1. Create a copy of your executable program Z##R_OPEN_SQL (suggested name:
Z##R_OPEN_SQL_PARAM, where ## is your group number). If you did not complete the
respective exercise, you can copy executable program S4D430_INTRO_S2, instead.
a) See the corresponding step in the previous exercise.
2. Change the definition of local data type ty_t_customers. Replace line type
S4d430_Customer_With_Revenue with your new CDS View
Z##_Customer_With_Parameter.
a) See source code extract from the model solution.
156
© Copyright. All rights reserved.
Lesson: Defining CDS Views with Input Parameters
3. Change the SELECT statement. In the FROM clause, replace CDS View
S4d430_Customer_With_Revenue with your new CDS View
Z##_Customer_With_Parameter. Supply the CDS View’s input parameter with system
field sy-datum.
a) See source code extract from the model solution.
4. Activate and test your program.
a) Perform this step as you did in the previous exercise.
Executable Program S4D430_PARAM_S1
REPORT s4d430_param_s1.
TYPES ty_t_customers TYPE STANDARD TABLE OF
s4d430_customer_with_parameter
WITH NON-UNIQUE KEY id.
DATA gt_customers TYPE ty_t_customers.
* ALV Processing
DATA go_salv TYPE REF TO cl_salv_table.
DATA gx_excp TYPE REF TO cx_salv_error.
* Selection Screen
PARAMETERS pa_city TYPE s_city DEFAULT 'New York' LOWER CASE.
START-OF-SELECTION.
* Data Retrieval
*************************************************************
SELECT *
FROM s4d430_customer_with_parameter( p_flightsbefore = @sy-datum )
WHERE city = @pa_city
ORDER BY city, name
INTO TABLE @gt_customers.
* output
*************************************************************
TRY.
cl_salv_table=>factory(
IMPORTING
r_salv_table = go_salv
CHANGING
t_table = gt_customers
).
* Display
*-------------------------*
go_salv->display( ).
CATCH cx_salv_error INTO gx_excp. "
MESSAGE gx_excp TYPE 'I'.
ENDTRY.
System Field as Default Value for Input Parameter
Use an annotation to link your input parameter with system field sy-datum.
© Copyright. All rights reserved.
157
Unit 4: Advanced Concepts
1. Edit your DDL Source Z##_CUSTOMER_WITH_PARAMETER. Use annotation
@Environment.systemField for the input parameter to use the system date as default
value.
a) See source code extract from the model solution.
2. Activate the DDL Source and open the data preview for the new CDS View.
Why are you still prompted to enter a value for the input parameter? And why is there no
default value for the parameter?
Annotation @Environment.systemField is only evaluated when the view is accessed from
L.
a) See the corresponding step in the previous exercise.
3. Return to your executable program Z##_PARAM_S1 and perform a syntax check.
a) Choose Sxntax Check from the toolbar.
Why do you suddenly get a syntax error that requires that you move the INTO clause to
the very end of the SELECT statement?
Annotation @Environment.systemField is a feature available as off release 7.50. As soon
as you use a 7.50 feature. your Open SQL statement has to fulfill the stricter syntax rules
introduced with this release.
4. Adjust the SELECT statement according to the new syntax rules of release 7.50: Move the
INTO clause to the very end of the statement.
a) See source code extract from the model solution.
5. Edit your program Z##_PARAM_S1. Copy the entire SELECT statement. In the copied
SELECT statement, remove the parameter passing (brackets after the name of the CDS
View).
a) See source code extract from the model solution.
6. Perform a syntax check to verify, that now a parameter passing is not needed anymore.
a) Choose Sxntax Check from the toolbar.
DDL Source S4D430_CUSTOMER_WITH_PARAMETER
...
define view S4d430_Customer_With_PARAMETER
with parameters
@EndUserText.label: 'Consider flights up to this date'
@Environment.systemField: #SYSTEM_DATE
P_FlightsBefore : abap.dats
as select
from S4d430_Booking_And_Customer as c
...
Executable Program S4D430_PARAM_S1
* Option 2: Do not provide a value
* (possible if parameter is linked to a system field)
************************************************************
158
© Copyright. All rights reserved.
Lesson: Defining CDS Views with Input Parameters
*
*
*
*
SELECT * FROM s4d430_customer_with_PARAMETER
WHERE city = @pa_city
ORDER BY city, name
INTO TABLE @gt_customers.
© Copyright. All rights reserved.
159
Unit 4: Advanced Concepts
LESSON SUMMARY
You should now be able to:
160
●
Define CDS Views with Input Parameters
●
Provide Values for Input Parameters of a CDS View
●
Specify a Default Value for an Input Parameter
© Copyright. All rights reserved.
Unit 4
Lesson 2
Building CDS Views with Associations
LESSON OBJECTIVES
After completing this lesson, you will be able to:
●
Define Views with Associations
●
Expose Associations
●
Use Exposed Associations in Path Expressions
●
Understand Filtered Associations
Syntax of Associations
CDS provides extended support for treating relationships between entities. Such
relationships are often reflected as foreign key relationships in the database, but in SQL the
relations are often concealed behind non-trivial join conditions.
This is cumbersome and error-prone for application developers, and requires considerable
effort when joins are to be reused.
•
The syntax of associations keeps the relations between data model entities visible. Path
expressions and filtered associations make it easier to read the CDS View definitions, as well
as the SELECT statements accessing the views.
• A High-value Wrapping of the Syntax for Joins
- Associations define relationships (they not just join data sources)
- Associations are translated into joins on database level
• Easier t.o Read
Associations may contain additional semantic information (e.g. cardinality)
Path expressions reveal the underlying data model and origin of data
- Filter conditions are easier to read than WHERE conditions or CASE-expressions
• Improved Performance
- Ej{posed associations are only evaluated when needed
J
r JOIN on Demand")
Figure 111: What Are Associations?
Although associations and joins look different, there is no difference on database level.
Eventually, any association is translated into an ordinary join. But in the case of so-called
exposed associations, it depends on the way a view is consume. The join is only executed if
the consumer requests data from the associated data source. This can have a positive effect
on the performance and sometimes is referred to as “JOIN on Demand”.
© Copyright. All rights reserved.
161
Unit 4: Advanced Concepts
View Definition with Association
I @Abap(atalog. s ql ViewName:
'S4D430_ASS01'
define view S4d430_Association_l as select
from spfli assoctataon to scer-r
on .spfli. carr-Id .. scarr. car-r-Id
{ key carrid,
key connid,
sea rr. carrname
---=-==-------
L
}
L
Association target
1
Name of data source
mandatory for all fields
from association target
---------------------�
View Definition with Join
@AbapCatalog.sqlViewName: '54D430_JOININN'
define view S4dl430_JOIN_ININER as select
from spfLi inner join scar-r
on
L
spfli.carrid
Name of data source only
mandatory for non-unique
field names
= scarr.carrid
{ key spfli.carrid,
key conrrid,
carrname
}
Figure 112: Example: Association Instead of Join
At first glance, associations are just another syntax for defining joins. In the example above,
the two FROM clauses only differ in the use of keywords "association to" or "inner join". The
ON condition remains exactly the same (though, strictly speaking, we must not refer to it as
“Join condition” any more).
There is also a small difference in the element list: In the element list of a join, specifying the
data source for a field is only mandatory for non-unique field names (like field name CARRID
in the example). In the field list of an view with association, all fields without an explicit source
are taken from the primary data source (table SPFLI in the example). For all fields from the
associated table, it is mandatory to specify the data source (field SCARR.CARRNAME in the
example).
View Definition with Associiation
@Abap(atalog.,:;qlViewName: 'S4D430_ASS01'
define view S4dl430_A.ssociation_l as select
from spfli association to scar-r
on spfli. carr-Ld = scarr. carr-Id
{ key carrid,
key connid,
scarr.carrname
}
Gorrespondiing SQl Create Statement
CREATE VIEW "54 .43 _ASSOl" .AS SELECT
"SPFL-". �MANDT" AS "!WJDT" I
"SPFI.-". '�CARRIO" I
"SJ:1-L.". CONNID",
"S?F:t·","C.TYFRO ",
"S?FLI n. -crrzto- I
"•A" ON (
Figure 113: Technical Realization of Associations
162
© Copyright. All rights reserved.
The SQL Create Statement of a CDS view definition visualizes its technical realization. The
SQL Create Statement for view definition above reveals, that on database level, it is nothing
more than a join definition.
Cardinality
( exactly one carrier
@AbapCatalog. sqlViewName; 'S40430_ASS02 •
define view S4d430_Association_2 as select
related to a oonnection)
from spf li as c
assocfatfonj t.. .1] to scar+ as _carrier
on c.carrid
=
_carrier.carrid
Name of the association
{
key c.carrid,
Ikey c.connid)
c.dtyfrom,
c .ct tyto,
Replaced with Alias in
SOL Create Statement
_carrier.carrname
}
Extract Fmm the SQL Create Statement
H=A ". Hl:A!, KNA.,Y�H
FR H j"SPF1 "
"C ... '"HtiNDI"
c
I.
"'CARRI
Ltf'T O TER O N rsdi.RR"
"C"L
= =:AO". "MMfDTH AND
H
-
..
....A
"iO�
-A '",, "CARR: ..
Figure 114: Example: Additional Semantics
When you define an association, you can use addition AS to specify an alias. This syntax looks
very similar to the definition of aliases in the join syntax. But strictly speaking, it is not an alias
for the data source but a name for the association.
The difference becomes clear when we look at the SQL Create Statement again:
In the SQL Create statement, the association name is replaced by a more generic alias ("A0"
in the example). This means that the association name is only a semantic information.
Hint:
It is recommended, but not a fixed rule, that names for associations begin with
character "_". A meaningful name for the association further improves the
readability of the view definition.
ERROR: undefined
OFFENDING COMMAND: ‘~
STACK:
Unit 4: Advanced Concepts
Associations and Cardinality
Cardinality is optlonal
- Default cardinality is (0 .. 1)
Minimum value is opttcnal
- Defau It Value for mimimum is O
[11 means [0 .. 11
[41 means (0 .. 41
[") means (0 .. "]
• Forbidden Values
- Minimum can not be '
- Maximum can not be O
Syntax Check for Maximum> 1
- Association cannot be used in a WHERE condition (syntax error)
- Association should not be used outside aggregate expressions (syntax warning)
J
Figure 115: Some Rules Regarding Cardinality
The list above shows some rules regarding cardinalities in associations.
There are a few short forms and defaults. And there are some forbidden values.
Specifying a cardinality with maximum larger than 1 can lead to the following syntax errors
and warnings:
●
●
164
Syntax error “Value-set associations are not allowed here” is issued of the association is
used in a WHERE condition.
Syntax warning “Association <…> can influence the cardinality of the resulting set” is
issued if the association is used in the element list.
© Copyright. All rights reserved.
Lesson: Building CDS Views with Associations
@AbapCatalog.sqlViewName: 'S4D430_ASSOWARN'
define view S4d430_Association_WARNING as select
from spfli as c
association[*]
to sf light as _flights
on c.carrid
and c. conn id
I I short for [ 0 .. "l
= _flights.carrid
= _fl i.ght s , conn id
{
Access to association
with cardina1llity [*]
increases result set
key carrid,
key conmd,
_flights. fldate
}
Result without field fldate
.... and with field fldat.e
t:'l RewO.t�
--------,
amid
AA
AA
AA
AA
AA
0017
AA
AA
ronnid
0017
0017
0017
0017
0017
0017
fl'dat•
2015-11·18
2.015-12·16
2.0lfi.-01-B
:?016-02-10
2l)1t;.03.(J!I
2.0lf>.OMJ6
Figure 116: Example: Syntax Warning for Cardinality [*]
Syntax of Exposed Associations
In the previous examples, the views directly accessed fields of the associated data source.
This kind of associations is called ad-hoc association.
•
The benefit of associations becomes clearer when looking at exposed associations.
@AbapCatalog.sqlViewName; 'S4D430_ASSOEXP'
define view S4d430_Assoc:iation_Exposed as select
from spfli as c
association[l] to scarr as _carrier
on c.carrid = _carrier.carrid
association[*] to sflight as _fli!ihts
on c.carrid
_flights.carrid
and c , conndd = _flights. conn id
Prerequisite: all fields
used in the ON condition
also in element llist
key c .. carrid,
key c. ccnndd ,
c.cityfrom,
c.cityto,
_carrier,
_flights
Association target
visible to consumer of
this CDS View
l
}
Figure 117: Example: Exposed Association
Instead of accessing individual fields of the associated data source, a CDS view can place the
association name itself in its element list. The association is then exposed to the consumer of
the CDS view, which is either another CDS View or an ABAP Open SQL statement. The
consumer of the view gets full access to all components of the associated data source.
© Copyright. All rights reserved.
165
Unit 4: Advanced Concepts
There is a prerequisite for exposing an association: All fields used in the ON condition of the
association have to be part of the element list. In the example above, field c.carrid is required
for exposing association _carrier. Fields c.carrid and c.connid are required for exposing
association _flights.
@AbapCatalog.sqlViewName; 'S4D430_ASSOEXP'
define view S4d430...;Association_Exposed as select
from spfli as c
association[l] to
on
association[*] to
on
and
scarr as _carrier
c.carrid = _carrier.carrid
sflight as _flights
c.carrid
_flights.carrid
c.connid"' _flights.connid
Exposed Associations
are not (yet) joined on
database level1
{
key c.carrid,
key c.connid,
c.cityfrom,
c .. dtyto,
_carrier,
_flights
}
CREATE VIEW' "S
43
ASSOEXP" AS SELECT
"C". "MANDT" nS .. �DT .. ,
.. c". "CARRI
.. ,
"C". "CONN!-",
No warning if association
with cardinality [1 is
. . c·•. "C.i.IYFRO •• ",
'"C". "C- tY!O"
::-RO·I "SPF'LI" "'C"
exposed
Figure 118: Difference Between Exposed and Ad-hoc Associations
First of all, by exposing an association, you do not preselect the fields of the data source
which you think might be of interest. You delegate this task to the consumer of the view. But
there is an important technical difference that becomes relevant if the consumer chooses not
to select any fields from the association.
The example above shows the SQL Create Statement for a CDS View with exposed
association. You can see that in the case of an exposed association the SQL View does not
immediately join the associated data source. The actual join of the data source is not done,
until the consumer actually accesses individual fields of the associated data source.
You can put it that way: By exposing an association, the actual join of the data sources is
postponed until it is clear that the consumer actually wants to see data from the associated
data source.
As a consequence, you can add any number of exposed associations to your view without
having to fear that you might create a SQL View with a monster join expression.
Note:
Because the join is not done yet, there is no syntax warning if an association with a
cardinality with maximum greater 1 is exposed.
166
© Copyright. All rights reserved.
Lesson: Building CDS Views with Associations
Template defineViewWithAssociation
x
CJ
Templetes
I
S<IKI "'"" o! lh� av•ilabl• �om;plot ...
rJh@.us.o<:illlicn can be w�d in lh! selKII litt M Yl'll!!!I M by ether
,.._ whict. ijle th,i .iew ,� , cltt� iou,ce.
finish
Figure 119: Template "defineViewWithAssociation"
There is a dedicated template for creating a view definition that contains an association to a
second data source.
Exposed Associations in Data Preview
� ll!i S4DA30_ASSOCIATIOt,t�POSED
� Gt
�
26 rows rel!rieved - 0 ms
connid
earrld
I
cityfrom
2407
2402
BERillN
0400
FRANKFURT
FRANKFURT
Q
Q\Jicl<: 111er on IFRANKFURTI
EID
Distinct v�lues fo,r I cityf,oml
Follow Association
Coi:iyrow
0783
lW
<;AN FRANCJ<;. ••
1699
om
0790
, _,.rriOI-<CIHI0 •. 11
+-i _flig;trt, - >light I O •. "
l
\!YORK
I FAAfll ...
t}
NEWYORiK
NEW YORK
NEWYORiK
NEWYORIK
ROME
ROME
ROME
0401
5S16
0017
dtyto
NEW YORK
NEWY,QRK
FRANKFURT
04oz
lis1of """'"1atlom
f.
FRANKFURT
BERLIN
NKFURT
FRANKFURT
FftANKFllRT
SANFll,AN ...
SAN,FP.AN ...
FRANKFURT
OSAKA
TOKYO
FIRANKFIIRT
Figure 120: Exposed Associations in Data Preview
If a CDS View definition contains exposed associations, you can evaluate these associations in
Data Preview as follows:
© Copyright. All rights reserved.
167
Unit 4: Advanced Concepts
1. Open the CDS View in Data Preview.
2. Choose one of the displayed rows, then click on the arrow next to the view name in the
header toolbar (see figure above).
10
Hint:
Alternatively, you can right-click the entry and choose Follow Association.
3. Choose an association from the list of available associations.
168
© Copyright. All rights reserved.
Unit 4
Exercise 12
Define a CDS View with Associations
Business Example
Template:
S4D430_BOOKING_AND_CUSTOMER (DDL Source)
Solution:
S4D430_ASSOCIATION (DDL Source)
Define a CDS View With An Association
Create a copy of your CDS View that joins booking data and customer data. Replace the join
with an (ad-hoc) association.
1. In your own Package, create a new DDL Source (suggested name: Z##_Association,
where ## stands for your group number).
2. In the new DDL Source, provide a suitable name for the DB View (suggested name:
Z##ASSO).
3. Open your DDL Source Z##_BOOKING_AND_CUSTOMER and copy the FROM clause and
the field list to the new DDL Source. If you did not complete the respective exercise, you
can copy from DDL Source S4D430_BOOKING_AND_CUSTOMER.
4. Edit the new DDL Source. In the FROM clause, replace the inner join with an association to
the CDS View with customer data.
Based on the data model, which would be the most appropriate cardinality for the relation
from a flight booking to the flight customer?
5. Add the cardinality information to the association statement.
6. Perform a syntax check and activate your new DDL Source.
Expose the Association
In the element list of your CDS view, comment out all elements that come from the associated
view with customer data. Expose the complete association, instead.
1. In the element list of your CDS view, place characters “//” in front of all fields starting with
“C.”.
© Copyright. All rights reserved.
169
Unit 4: Advanced Concepts
Hint:
You can comment out several lines by marking them and hitting keys Strg +
<.
2. At the end of the element list, add the name of the association.
3. Apply the recommended naming rule for associations.
Note:
The rule recommends meaningful aliases for associations, starting with an
underscore (“_”).
4. Activate your new DDL Source.
Use an Exposed Association in Data Preview
Open the data preview for your new CDS View and follow the association to the flight
customer.
1. Open data preview for your new CDS View.
2. Choose a flight booking and display details of the flight customer associated to this
booking.
170
© Copyright. All rights reserved.
Unit 4
Solution 12
Define a CDS View with Associations
Business Example
Template:
S4D430_BOOKING_AND_CUSTOMER (DDL Source)
Solution:
S4D430_ASSOCIATION (DDL Source)
Define a CDS View With An Association
Create a copy of your CDS View that joins booking data and customer data. Replace the join
with an (ad-hoc) association.
1. In your own Package, create a new DDL Source (suggested name: Z##_Association,
where ## stands for your group number).
a) See the corresponding step in the previous exercise.
2. In the new DDL Source, provide a suitable name for the DB View (suggested name:
Z##ASSO).
a) See source code extract from the model solution.
3. Open your DDL Source Z##_BOOKING_AND_CUSTOMER and copy the FROM clause and
the field list to the new DDL Source. If you did not complete the respective exercise, you
can copy from DDL Source S4D430_BOOKING_AND_CUSTOMER.
a) See the corresponding step in the previous exercise.
4. Edit the new DDL Source. In the FROM clause, replace the inner join with an association to
the CDS View with customer data.
a) Instead of inner join <...> as C write association to <...> as C.
b) See source code extract from the model solution.
Based on the data model, which would be the most appropriate cardinality for the relation
from a flight booking to the flight customer?
As exactly one flight customer is assigned to every single flight booking. the most
appropriate cardinality is 1..1.
5. Add the cardinality information to the association statement.
a) Add [1..1] immediately after key word ASSOCIATION.
b) See source code extract from the model solution.
6. Perform a syntax check and activate your new DDL Source.
© Copyright. All rights reserved.
171
Unit 4: Advanced Concepts
a) See the corresponding step in the previous exercise.
Expose the Association
In the element list of your CDS view, comment out all elements that come from the associated
view with customer data. Expose the complete association, instead.
1. In the element list of your CDS view, place characters “//” in front of all fields starting with
“C.”.
Hint:
You can comment out several lines by marking them and hitting keys Strg +
<.
a) See source code extract from the model solution.
2. At the end of the element list, add the name of the association.
a) See source code extract from the model solution.
3. Apply the recommended naming rule for associations.
Note:
The rule recommends meaningful aliases for associations, starting with an
underscore (“_”).
a) Replace as C with as _Customer.
b) Adjust all references to the alias.
c) See source code extract from the model solution.
4. Activate your new DDL Source.
a) See the corresponding step in the previous exercise.
Use an Exposed Association in Data Preview
Open the data preview for your new CDS View and follow the association to the flight
customer.
1. Open data preview for your new CDS View.
a) See the corresponding step in the previous exercise.
2. Choose a flight booking and display details of the flight customer associated to this
booking.
a) In the result list, right-click the booking for which you want to see customer details.
b) Choose Follow Association.
c) From the list of available associations, choose the one that leads to flight customer
data.
DDL Source S4D430_ASSOCIATION
@AbapCatalog.sqlViewName: 'S4D430ASSO'
@AbapCatalog.compiler.compareFilter: true
@AbapCatalog.preserveKey: true
172
© Copyright. All rights reserved.
Lesson: Building CDS Views with Associations
@AccessControl.authorizationCheck: #CHECK
@EndUserText.label: 'Solution: Exposed Association'
define view S4d430_Association as
select
from S4D430_Booking as b
association [1..1] to s4d430_Customer as _Customer
on b.customid = _Customer.id
{
key b.carrid,
key b.connid,
key b.fldate,
key b.bookid,
b.customid,
b.agencynum,
b.amount,
b.currency,
b.days_ahead,
_Customer // Make association public
// c.name,
// c.street,
// c.postcode,
// c.city,
// c.country
}
© Copyright. All rights reserved.
173
Unit 4: Advanced Concepts
Path Expressions in CDS DDL
i
@AbapCatalog.sqlViewName: 'S4D430_PATHEXPR1'
Read from CDS View
that exposes
Associations
defin1e view S4d430,_Path_Expressions_1 as select
from S4d430_Associa,tion_Exposed as c
{
key carr-Id,
key connidJ
Read field carrname
from target of
c .. _carrier. carrnaae as carrier_name;
association _carrier
_flights
Propagate association _Jlights
(Do not use it directly)
CR!ATt VIEW nS4 430 PA l'!EXPR "
as
S!tLE.C'.t
"C".n!-oomf" JI.S "MAJf[)f•,
"C"". "CAAAID",
·c··. "CONNID",
"-AO". �CA.�lUIA.l.!EH AS "CAREUER NllME"
FROM "SIID,30 ASSOEX?'' "C" LEn-Ov""I'ER JOIN "SCA..i:l..�" "-AO" 0. I
'"C ... "HDDT':" • "'11,J;.Q N. "Mi!ND!" AND
'"C". "C.MUl " " ·�AO"."' MA "
Join of SCARR,
but no join of SFLIGHT
Figure 121: Example: Use Exposed Associations in a View Definition
The CDS View in the example above reads data from a CDS View that contains exposed
associations.
The element list contains a path expression to read field carrname from the association target
of association _carrier.
Association _flights is not used directly. Instead, it is propagated, which means it is exposed
again under the same name.
In the SQL Create Statement for this view, we find a join of the SQL view created for CDS View
S4d430_Association_Exposed with database table SCARR. This is because SCARR is the
target of association _carrier.
Table SFLIGHT, the target of association _flights, is not joined here. This is because the
association is not used but only exposed.
Note:
To define this view, it is not necessary to know that SCARR is the target of
association _carrier. Nor is it necessary to know the details of the relation between
connections and carriers, i.e., the join condition.
174
© Copyright. All rights reserved.
Lesson: Building CDS Views with Associations
I @Aba pCatalog. sql ViewName:
"S4D430_PATHEXPR2,
define view S4d430_Pa.th_Expressions_2 as select
from S4d430_Path_Expressions_1 as c
key carr-Ld ,
Read field seatsocc
from target of
association _flights
key connid,
ca,rrier_name,
sum(c._flights.seatso,cc) as occupied_total
group by carrid,
ccnrud,
L
carrier_name
CREA-:: V!Eti "S4 43
·c·. "MANDT"
AS
·c· - "CAAAl!l",
PAT!!�.i!'R.2" AS SELE.CT
AMiNDr·.
·c·. "C<JN!i!il",
Now also talble
SFUGHT is joined
"C" • "CARR! !:R.Jil1M1:",
Sir.,![
"•AO" , • S�TSOCC"
I AS "SE'.ATS_TC>TAL"
!'!\<*! ·s�D�JO l'J\:T!!E:XPRl. ·c· L:E,T our� JOU. "Sfl.IG!!T" "-.AD" OH (
"C" • "CMtltlii" • "II.AO",. "CllR&ID" .WU
·c· . "CO!ffi!O" • -. ", "Co+mID"
·c· . -�or • ··AO·. "IWl'DT •
WO
Figure 122: Example: Propagation of Associations
The CDS View in this example reads from the CDS View of the previous example.
The element list contains a path expression to read field seatsocc from the association target
of association _flights.
In the SQL Create Statement for this view, we find a join of the SQL View created for CDS view
S4d430_Path_Expressions_1 with table SFLIGHT, the target of association _flights.
•
Path Expressions in Open SQL
SELECT FROM s4d430_association_exposed AS c
FIELDS carrid,
connid,
Prefix ,.\" for all
association names
Component selector j-"
(in CDS DDL it is ,,. ")
\_carrler-carrnane,
Optional:: With Alias .c"
for the data source
c-\_carrier-currcode
Pa�h expressions
WHERE c-\_carrier-currcode
INTO TABLE @gt_data.
'USO'
supported in all
clauses
l
Figure 123: Example: Use Exposed Associations in Open SQL
As of Release 7.50, path expressions also exist in Open SQL. They are supported in all
clauses, e.g. the field list, the WHERE clause, the GROUP BY clause, the HAVING clause.
Compared to path expressions in CDS DDL, the following important differences exist
regarding the syntax:
© Copyright. All rights reserved.
175
Unit 4: Advanced Concepts
●
Prefix "\" is needed for association names
●
Component selector is "-" (in CDS DDL it is ".")
Syntax of Filtered Associations
DDL Source
from tl association t.o t2 as _asso
onl<on-condition>
{
I
_as so Qdil ter-condi hon >U . field_,
}
SQL View Definition
FROM Tl LEFT OUTER JOIN T2
ON <on-condition>
AND <filter-condition>
Figure 124: Filtered Associations – The Principle
Path expressions in CDS DDL can be extended using a filter condition.
The filter condition becomes part of the ON - condition, when the system translates the path
expression into a join on database level.
I»
Note:
Filter conditions are currently not supported in Open SQL path expressions.
@Abap(ata og.sq1v·ewName: ,S4D430_ASSOFILT'
define view S4d430--'Association_FILTERED
with parameters
language : syst_ l angu @<Environment. systemFie ta: #SYSTEM_ LANGUAGE
as select
from scarr as a
association to tcurt as ....:currency
on a .cur re ode = _currency. waers
and _currency.spras
II
=
Do not restrict to one
language in the
ON condition
$parameters.language
j
{
carr-Ld,
car rname,
curr-code,
$parameters.language as lang,
But use a filter condition
in the Path Expression
_currency[spras = $parameters.language] .ktext as currency_name
}
Figure 125: Example: Filter Condition in Path Expression
176
© Copyright. All rights reserved.
Lesson: Building CDS Views with Associations
In this example, table tcurt is associated to table scarr (master data for airlines). Table tcurt is
a so-called text table. It contains names and descriptions for currencies in many different
languages. The ON condition of the association defines the basic foreign key relation between
the two tables, i.e., the currency code in table scarr (field currcode) is linked to the key field
waers in table tcurt.
This association links one carrier with all descriptions of its local currency, independent of the
language.
Instead of restricting the selection to one language in the ON condition of the association, the
example uses a filter condition in the path expression. Technically, that is on the database, the
result is the same. But with the filter condition in the path expression, it becomes clearer
which conditions are part of the foreign key relation, and which conditions reflect an
additional selection.
• Allowed Operators
• Left-hand Side
- Must be a field of association target
• Right·hand Side
- field of association target
- literal
- parameter
- session variable
I
Figure 126: Rules for Filter Conditions
When implementing a filter condition, the following rules apply:
●
●
●
All relational operators are allowed ( =, <, >, <=, >=, <> ).
The left-hand side of the condition expects a field of the association target (a field of
_currency in our example).
The right-hand side can be another field of that target data source, a literal, a parameter,
or a session variable.
© Copyright. All rights reserved.
177
Unit 4: Advanced Concepts
Cardinality in Filtered Associations
@Abapcatalog. sql ViewName: 'S4D430_FI L TCARD'
@EndUserText. label: "Demo: Cardinality in Filtered Asso."
define view S4D430_Asso_Filter_Cardinali'ty
with parameters
language : syst_Langu @<Environment. systemFieLd.: #5YSTEM_LANGUAGE
as select
.Foreign key relation has
from scarr as a
cardinalirty 0 .. * ·•
association[*] to tcurt as _currency
on a.cur-r-code = _currency.waers
{
car rid,
car-rname,
cur re ode,
$parameters.language as lang,
.But flllter condition
reduces this to 0 .. 1 •
_currency[l: spr-as .. $parameters. language]. ktext as currency_name
}
]
Figure 127: Example: Cardinality in Filtered Associations
The example above contains an association of table TCURT to table SCARR. The correct
cardinality for this association is 0..*: The local currency code of one carrier can have an
arbitrary number of texts in table tcurt — one for each language that is maintained.
We already learned that, normally, cardinality * leads to syntax warnings and even errors once
the association is used in path expressions.
In our example, the filter condition reduces the cardinality of the association to "0..1": For a
given language, TCURT contains a maximum of one entry per currency code.
To document this – and to make the syntax warnings and errors go away – you can specify
cardinality "1" in the filter condition of a path expression.
Note:
It is not allowed to specify a cardinality in a path expression without a filter
condition.
178
© Copyright. All rights reserved.
Lesson: Building CDS Views with Associations
Annotation compareFilter
from ti association to t2 as _asso
on <on-condition>
With Value False
L
{
...
_asso><-------,c .fieldl.,
_asso <
].field2,
... }
_J
With Value True
FROM Tl LEFT OUTER JOIN T2 AS AO
ON <on-condition>
AND <filter-condition>
FROM Tl LEFT OUTER JOIN T2
ON <on-condition>
AND <filter-condition>
LEFT OUTER JOIN T2 AS Al
ON <on-condition>
AND <filter-condition>
Figure 128: Annotation AbapCatalog.compiler.compareFilter
By default, every new path expression with a filter condition, will lead to a separate join in the
generated SQL View. This happens even if the filter conditions are identical (see our example
above and the SQL CREATE statement on the left).
ABAP annotation AbapCatalog.compiler.compareFilter can be used to specify whether the
filter conditions are compared for the path expressions of a view. If the filter condition
matches, the associated join expression is created only once, which generally improves
performance.
I»
Note:
The results sets of both configurations can differ.
© Copyright. All rights reserved.
179
Unit 4: Advanced Concepts
-i
@AbapCatalog.sqlViewName: 'SD430_FILTCOMP'
oompareFilter is
switched off
@Abapcatalog. compiler. c,ompareF 1l ter: false
define view s404;0_Asso_Filt:er_Compare
with parameters
language : syst_ Langu @<Environment. systemField: #SYSTEM_ LANGUAGE
as select
from scarr as a
association to tcurt as _currency
on a .. currcode - _currency. waers
{
car rid,
Two separate joins
for the identical paths
carr-name,
cur re ode,
$parameters.language as lang,
_currency[spras
_:currency[spras
.$parameters .. language] . kt ext as currency_name.,
$parameters. language] .1 text as curr desceaptdon
}
___- _
_J
Figure 129: Example with compareFilter: False
In the example above, the filter conditions in the two path expressions are identical.
Annotation ABAPCatalog.compiler.compareFilter is listed with value false. This makes the
system generate two separate joins of scarr and tcurt to retrieve fields ktext and ltext. With
value true, the system would compare the filters, realize that they are identical, and use just
one join to retrieve the two fields.
Note:
All data definition templates contain annotation
ABAPCatalog.compiler.compareFilter with value true.
180
© Copyright. All rights reserved.
Unit 4
Exercise 13
Use a CDS View with Associations
Business Example
Template:
S4D430_CUSTOMER_WITH_PARAMETER (DDL Source)
S4D430_PATH_T1 (Executable Program)
Solution:
S4D430_CUSTOMER_WITH_PATH (DDL Source)
S4D430_PATH_S1 (Executable Program)
Use an Exposed Association in Another CDS View
Create a copy of your CDS View that aggregates booking data per customer. Instead of
reading from a CDS View with a join, read from the CDS view with an association.
1. In your own Package, create a new DDL Source (suggested name:
Z##_Customer_With_Path, where ## stands for your group number).
2. In the new DDL Source, provide a suitable name for the DB View (suggested name:
Z##CUSTASSO).
3. Open your DDL Source Z##_CUSTOMER_WITH_PARAMETER and copy the FROM clause
and the field list to the new DDL Source. If you did not complete the respective exercise,
you can copy from DDL Source S4D430_CUSTOMER_WITH_PARAMETER.
4. Edit the new DDL Source. Replace the CDS View in the FROM clause with your CDS View
Z##_Association, which contains an exposed association. If you did not complete the
respective exercise, you can read from CDS View S4d430_Association, instead.
5. Perform a syntax check.
Why do you get syntax errors?
How can you read the customer-related information?
6. Use path expressions to read the flight customer data from the associated data source.
7. Perform a syntax check and activate your new DDL Source.
© Copyright. All rights reserved.
181
Unit 4: Advanced Concepts
Use an Exposed Association in Open SQL
Access your CDS View with exposed association in Open SQL. Use path expressions to follow
the association.
1. Create a copy of executable program S4D430_PATH_T1 (suggested name: Z##R_PATH,
where ## is your group number).
2. Change the SELECT statement. Replace the CDS View in the FROM clause with your CDS
View Z##_Association. If you did not complete the respective exercise, you can use CDS
View S4d430_Association, instead.
I»
Note:
Do not adjust the definition of local data type ty_s_customer!
3. Perform a syntax check for your executable error.
Why do you get syntax errors?
How can you access the customer-related information, now?
4. In your SELECT statement, use a path expression for all flight customer-related fields. Do
not forget fields in the WHERE clause and ORDER BY clause.
Hint:
Path expressions in Open SQL require a backslash (character “\”) in front of
each association name and dash (character "-") is used as component
selector.
5. Activate and test your program.
182
© Copyright. All rights reserved.
Unit 4
Solution 13
Use a CDS View with Associations
Business Example
Template:
S4D430_CUSTOMER_WITH_PARAMETER (DDL Source)
S4D430_PATH_T1 (Executable Program)
Solution:
S4D430_CUSTOMER_WITH_PATH (DDL Source)
S4D430_PATH_S1 (Executable Program)
Use an Exposed Association in Another CDS View
Create a copy of your CDS View that aggregates booking data per customer. Instead of
reading from a CDS View with a join, read from the CDS view with an association.
1. In your own Package, create a new DDL Source (suggested name:
Z##_Customer_With_Path, where ## stands for your group number).
a) See the corresponding step in the previous exercise.
2. In the new DDL Source, provide a suitable name for the DB View (suggested name:
Z##CUSTASSO).
a) See source code extract from the model solution.
3. Open your DDL Source Z##_CUSTOMER_WITH_PARAMETER and copy the FROM clause
and the field list to the new DDL Source. If you did not complete the respective exercise,
you can copy from DDL Source S4D430_CUSTOMER_WITH_PARAMETER.
a) See source code extract from the model solution.
4. Edit the new DDL Source. Replace the CDS View in the FROM clause with your CDS View
Z##_Association, which contains an exposed association. If you did not complete the
respective exercise, you can read from CDS View S4d430_Association, instead.
a) See source code extract from the model solution.
5. Perform a syntax check.
a) See the corresponding step in the previous exercise.
Why do you get syntax errors?
The customer- related fields (NAME. STREET. POSTCODE. CITY. COUNTRY) are not
contained in the new data source.
© Copyright. All rights reserved.
183
Unit 4: Advanced Concepts
How can you read the customer-related information?
Use the association in path expressions.
6. Use path expressions to read the flight customer data from the associated data source.
a) Use path expressions like c._Customer.name.
b) See source code extract from the model solution.
7. Perform a syntax check and activate your new DDL Source.
a) See the corresponding step in the previous exercise.
DDL Source S4D430_CUSTOMER_WITH_PATH
@AbapCatalog.sqlViewName: 'S4D430_CUSTPATH'
@AbapCatalog.compiler.compareFilter: true
@AccessControl.authorizationCheck: #CHECK
@EndUserText.label: 'Solution: Path Expressions in CDS DDL'
define view S4d430_Customer_With_Path
with parameters
@EndUserText.label: 'Consider flights up to this date'
@Environment.systemField: #SYSTEM_DATE
P_FlightsBefore : abap.dats
as select
from S4d430_Association as c
{
key c.customid as id,
c._Customer.name,
c._Customer.street,
c._Customer.postcode,
c._Customer.city,
c._Customer.country,
sum(c.amount) as amount @<Semantics.amount.currencyCode:
'currency',
c.currency,
avg(c.days_ahead) as days_ahead
}
where c.fldate < $parameters.P_FlightsBefore
group by
c.customid,
c._Customer.name,
c._Customer.street,
c._Customer.postcode,
c._Customer.city,
c._Customer.country,
c.currency
Use an Exposed Association in Open SQL
Access your CDS View with exposed association in Open SQL. Use path expressions to follow
the association.
1. Create a copy of executable program S4D430_PATH_T1 (suggested name: Z##R_PATH,
where ## is your group number).
a) See the corresponding step in the previous exercise.
2. Change the SELECT statement. Replace the CDS View in the FROM clause with your CDS
View Z##_Association. If you did not complete the respective exercise, you can use CDS
View S4d430_Association, instead.
184
© Copyright. All rights reserved.
Lesson: Building CDS Views with Associations
I»
Note:
Do not adjust the definition of local data type ty_s_customer!
a) See source code extract from the model solution.
3. Perform a syntax check for your executable error.
a) See the corresponding step in the previous exercise.
Why do you get syntax errors?
The customer- related fields (NAME. STREET. POSTCODE. CITY. COUNTRY) are not
contained in the new CDS View. directly.
How can you access the customer-related information, now?
Use the association in path expressions.
4. In your SELECT statement, use a path expression for all flight customer-related fields. Do
not forget fields in the WHERE clause and ORDER BY clause.
Hint:
Path expressions in Open SQL require a backslash (character “\”) in front of
each association name and dash (character "-") is used as component
selector.
a) Your path expressions should look like \_Customer-name, \_Customer-street,
etc.
b) See source code extract from the model solution.
5. Activate and test your program.
a) Perform this step as you did in the previous exercise.
Executable Program S4D430_PATH_S1
REPORT s4d430_path_s1.
TYPES: BEGIN OF ty_s_customer,
id TYPE s4d430_customer_with_parameter-id,
name TYPE s4d430_customer_with_parameter-name,
street TYPE s4d430_customer_with_parameter-street,
postcode TYPE s4d430_customer_with_parameter-postcode,
city TYPE s4d430_customer_with_parameter-city,
country TYPE s4d430_customer_with_parameter-country,
amount TYPE s4d430_customer_with_parameter-amount,
currency TYPE s4d430_customer_with_parameter-currency,
days_ahead TYPE s4d430_customer_with_parameter-days_ahead,
END OF ty_s_customer.
TYPES ty_t_customers TYPE STANDARD TABLE OF ty_s_customer
© Copyright. All rights reserved.
185
Unit 4: Advanced Concepts
WITH NON-UNIQUE KEY id.
DATA gt_customers TYPE ty_t_customers.
* ALV Processing
DATA go_salv TYPE REF TO cl_salv_table.
DATA gx_excp TYPE REF TO cx_salv_error.
* Selection Screen
PARAMETERS pa_city TYPE s_city DEFAULT 'New York' LOWER CASE.
START-OF-SELECTION.
* Data Retrieval
*************************************************************
SELECT
FROM s4d430_association
FIELDS customid as id,
\_customer-name,
\_customer-street,
\_customer-postcode,
\_customer-city,
\_customer-country,
sum( amount ) as amount,
currency,
avg( days_ahead ) as days_ahead
WHERE \_customer-city = @pa_city
and fldate < @sy-datum
group by customid,
\_customer-name,
\_customer-street,
\_customer-postcode,
\_customer-city,
\_customer-country,
currency
ORDER BY \_customer-city, \_customer-name
INTO TABLE @gt_customers.
* output
*************************************************************
TRY.
cl_salv_table=>factory(
IMPORTING
r_salv_table = go_salv
CHANGING
t_table = gt_customers
).
* Display
*-------------------------*
go_salv->display( ).
CATCH cx_salv_error INTO gx_excp. "
MESSAGE gx_excp TYPE 'I'.
ENDTRY.
186
© Copyright. All rights reserved.
Lesson: Building CDS Views with Associations
LESSON SUMMARY
You should now be able to:
●
Define Views with Associations
●
Expose Associations
●
Use Exposed Associations in Path Expressions
●
Understand Filtered Associations
© Copyright. All rights reserved.
187
Unit 4
Lesson 3
Enhancing a CDS View
LESSON OBJECTIVES
After completing this lesson, you will be able to:
●
Understand the Concept of CDS View Enhancements
●
Enhance a CDS View
Reminder - Append View
Software Provider (e.91. SAP)
Customer
ABAP
Repository
(Dictionary)
Database Object (= Database View)
I
I
I
I
I
I
Database
I
Figure 130: Reminder: Append Views for Classical Database Views
Database views delivered by SAP can be enhanced by partners and customers using views
known as append views, without making any modifications.
Further fields from basis tables in the database view can be added to append views as view
fields.
Append views cannot be used to add further basis tables to the view or to modify the join
conditions or selection conditions of a database view.
An append view is assigned to exactly one database view. More than one append view can be
created for a database view.
188
© Copyright. All rights reserved.
Lesson: Enhancing a CDS View
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LOB H,n111e Sttuc:tur,: ...
Dicliolt8,Y.
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'l/lewfleld
r!!All:Dl
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Z4tl430 .APPEND
c
n:Ell0)4
l.!R?=
IIHO
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Figure 131: Example: Creating a Classical Append View
In the example, database view S4D430_APPENDED has six fields in its field list. Append View
Z4D430_APPEND adds fields AIRPFROM and AIRPTO.
CDS View Extensions
Software Provider ( e.g. SAP}
Customer
CDS View Definition
CDS Extend View Definiitiori
Define View •.. AS •••
Extend View ••• WITH •••
SQL View
ASAP
Repository
(Dictionary)
(generated)
Database Obj,ect {= SQL View)
I
I
I
I
Database
I
Figure 132: CDS View Extensions
CDS View Extensions are defined in dedicated DDL Sources via DDL statement EXTEND
VIEW.
Every DDL Source with a CDS view extension defines two objects: The actual CDS view
extension and an Append View. This corresponds to the two objects defined by a standard
DDL: The CDS View and the SQL View.
© Copyright. All rights reserved.
189
Unit 4: Advanced Concepts
DDL Source With View Extension (Created by Custom,er)
@AbapCatalog. sql ViewAppendName: 'Z4D430 EX TENDA'
extend view S4d430 Externd Tar .et A
with Z4d430 Extend View A
{ c .atr-pfr-om,
Points at an existing
CDS View
c.airpto
}
DDL Source· With View .DefiniUo·n (Created by Softwar·e· Provider)
@Abapcatalog. sqlViewName:
'S4D430_E:XTTARGA'
define view!S4d!430 Externd Target Aias select
from spfli as c
inner join scarr as a
on c.carrid
{ key c.carrid,
=
a.carrid
key c.connid,
c.dtyfrom,
c.dtyto,
a.c:arrname
}
Figure 133: Example: CDS View and CDS View Extension
In this example, CDS View S4d430_Extend_Target _A contains six elements in the element
list. CDS View extension Z4d430_Extend_View_A adds fields airpfrom and airpto to this list.
The link between the two DDL Sources is established through the CDS view name after key
word EXTEND VIEW.
I»
190
Note:
The name of the SQL view cannot be specified here.
© Copyright. All rights reserved.
Lesson: Enhancing a CDS View
Element List
• literals, fields, expressions, functions
• Input parameters
• Path expreeeions
• Aggregates (as of 7. 51 , only
if target already contains aggregates)
• Associations
• View Extension can add asseclatlons
• G,ROUP BY Clause fas of release7.51)
• Only if target view contains a GROUP BY clause
• Ma.ndatory for new elements that are not aggregates
UNION(ALL) Statements (as of release 7.51)
• Mandatory if target view contains UNION (ALL) statements
•Same number of UNION(ALL) Statements required
Figure 134: Syntax of View Extensions
Like classical Append Views, CDS View Extends can add elements to the SELECT list. New is
the fact that an extend view can also define additional associations. This can be used, for
example, to define an association to a customer-specific database table or CDS View.
I»
Note:
A CDS View Extend may contain associations but no direct joins.
As of release 7.51, it is also possible to extend views that contain aggregations and/or
UNIONs. But to do so, the target view has to actively allow this via annotation
AbapCatalog.viewEnhancementCategory.
© Copyright. All rights reserved.
191
Unit 4: Advanced Concepts
DDL Source With View Extension
@AbapCatalog. sql ViewAppendName: 'Z4D430_EXTENDB'
extend view S4d430_Extend_Target_B
with Z4d430 Extend View B
association to sairport as _from
,on c .airpfrom = _from .. id
association to sairport as _to
on c.airpto
=
_to.id
{
c .airpfrom,
! _from. name as airpfrom_name
Add assoclatons
to target view
I
Use elements of the
:1
c . count ryf r,
c Lajrpto
to.name as airpto name1
associated data sources
c . count ryto
}
Figure 135: Example: CDS View Extension with Association
In this example, CDS View S4d430_Extend_Target _B CDS View is extended with CDS View
Extension Z4d430_Extend_View_B.
This view extension not only extends the field list. It also adds two associations to table
sairport.
Note:
Instead of using fields of the associated data sources directly, the view extensions
could also have exposed the new associations.
192
© Copyright. All rights reserved.
Lesson: Enhancing a CDS View
DDL Source With Vi,ew Extension (Created by Custom,er)
end Name; I• S4Q430 EXTENDC'i
extend view S4D430 Extend Tar etc
with S4D430 EXTEND VIEW C
@AbapCatalo . s l ViewAi
{
Addition al aggregations
in element list
city,
countryJ
miax( _booking. fldate ) as la,st_booking
}
group by city1
Extension of the
GROUP BY clause
country
union
{
city,
country,
max ( _booking. fl date ) as l.ast_booldng
l
l
Key word UNION,
followed by extension
for the other SELECT
}
gr-oup by crty,
country
Figure 136: CDS View Extension with GROUP BY and UNION
In this example, CDS View S4d430_Extend_Target_C contains two SELECT statements linked
with a UNION statement. Each SELECT statement has an aggregation expression in the
element list and a corresponding GROUP BY clause.
CDS View extension Z4d430_Extend_View_C reflects this structure: It contains the
extensions for both SELECT statements, linked with key word UNION.
In both SELECT statements, the extension adds fields city and country to the element list and
expands the GROUP BY clause accordingly.
Note:
Extensions with GROUP BY and UNION are only possible if explicitly allowed by the
extended view via annotation @AbapCatalog.viewEnhancementCategory.
© Copyright. All rights reserved.
193
Unit 4: Advanced Concepts
Template extendView
x
Cl
I
f2I Us�lh• �•dod l•mpl•I•
(!JD6ine\liow
(!JDdint \litw,,,;lh Join
ID Ddin• View walh Am,�i1ticn
[Extend� an e:isling ,,;...., by ad<iin9 the o;p«rued elom•ni•
["''l.htc itr«t li1t cftl:itcvii'.w u!in.g a vitw tnMM.Hl'l�n.t.
Nert
Figure 137: Template "ExtendView"
There is a dedicated template for creating the definition of a view extension. After creating the
DDL Source, you have to specify the name of the CDS View you want to extend, the name of
the new CDS entity (View extend), and the name of the SQL View append.
Recommendations and Restrictions for View Extensions
Recommendations
• Naming
- (Customer) Namespace for repository objects (DDL Source and SQLAppend View)
- Uncommon names for additional elements and associations (to avoid later conflicts)
Identical Name for DDL Source and CDS Entity (besides upper/lower case)
• CDS Views from Basis Packages
Contact SAP before you extend CDS Views from Basis Packages
Rest ictions
• No Renaming After Transport
- Name of CDS View Extend and SQLAppend View can not be changed after first
transport of DDL Source
• No Additional Key Fields
- Prefix KEY is not allowed in CDS View Extends
J
Figure 138: Recommendations and Restrictions
When extending CDS Views, it is advisable to carefully choose the names of repository objects
and additional entities to avoid conflicts in future upgrades.
194
© Copyright. All rights reserved.
Lesson: Enhancing a CDS View
Placing the additional repository objects in an appropriate namespace is one of the
recommendations. The other refers to the additional element list entries and associations. By
using very common names, you increase the risk of conflicts with later additions in the
standard.
I»
Note:
For append fields to transparent tables, the recommended namespace is ZZ and
YY. No such namespace exists for CDS View extends.
Like with CDS Views in general, it is advisable but not mandatory to use the same name for
the DDL Source and the CDS entity.
The most important restriction also refers to naming: After a DDL Source has been
transported from the development system, the names of the SQL Append View and the CDS
View Extend are fixed and cannot be changed any more.
Annotation viewEnhancementCategory
An notation AbapCatalog. viewEnhancementCa:tegory[l
- Restricts the extensibility of a CDS View
- Comma-separated list of values in square brackets
• Possible Values
- #NONE
- #PROJECTION_LIST
- #GROUP BY
- #UNION
Allowed Combinations
- #NONE cannot be combined with other values
- #GROUP BY and #UNION require #PROJECTION�LIST
Default Value
- #PROJECTION_LIST
l
Figure 139: Restricting Extensibility (as of Release 7.51)
As of Release 7.51, the extensibility of a CDS View may be restricted by annotation
AbapCatalog.viewEnhancementCategory.
The annotation may be used with a comma-separated list of values in sqare brackets.
The following values exist:
#NONE
No extensions are allowed. This Value cannot be combined with other values.
#PROJECTION_LIST
Extensions of the SELECT list and additional associations are allowed; extensions of CDS
views whose SELECT lists contain aggregate expressions or have a UNION clause must
be permitted using further values.
#GROUP BY
© Copyright. All rights reserved.
195
Unit 4: Advanced Concepts
Aggregated or non-aggregated elements are allowed to be added to a SELECT list
with aggregated expressions and the associated extensions of the GROUP-BY clause are
also permitted;
caan only be specified together with #PROJECTION_LIST.
#UNION
Extensions of the SELECT list of a CDS view with a UNION clause are allowed; can only be
specified together with #PROJECTION_LIST.
If the annotation is used without square brackets or if the annotation is missing at all, the
view's extensibility is as if the annotation had been specified with value
#PROJECTION_LIST.
Navigation from Extension Target to View Extension
1- fAbapCatalog. sqlViewllal!".e: 'S4D430_EXTTAAGET'
2 fAbapCatalog.c: piler.c pareFil er: true
3 fAc::cessControl. authori:.".ationChedc: IICHECI<
@EndUser-Text
.
·
label: 'De:IIO: Tar e:t for- S4d430_Ext:end_View'
...
define view ·, · ,
• . :
.
,
from �pi'H !IS c
lS
8
9
-
.
-- -
S4d430_Extend_Target
Di!mo, .arge1 for S4d430_Extend.Vi=
19
11
12
13
14
15
16
>
Figure 140: Extended View in DLL Source Editor
You can see it directly in the DDL Source if there are any extends for this particular CDS View.
If one or more CDS View Extends point to this CDS View, a spiral-shaped symbol appears on
the left of the DEFINE VIEW Statement. When you place the pointer over this symbol, a dialog
box opens with a list of the existing extensions. Open the definition of the CDS View Extend by
clicking on its name in the list.
196
© Copyright. All rights reserved.
Unit 4
Exercise 14
Enhance a CDS View
Business Example
Template:
S4D430_ASSOCIATION (DDL Source)
Solution:
S4D430_EXTENDED (DDL Source)
S4D430_EXTENSION (DDL Source)
Create a Copy of the Template CDS View
Create a copy of your CDS View that exposes an association. If you did not complete the
respective exercise, you can copy from CDS View S4d430_Association.
1. In your own Package, create a new DDL Source (suggested name: Z##_Extended, where
## stands for your group number).
2. In the new DDL Source, provide a suitable name for the DB View (suggested name:
Z##EXTENDED).
3. Open your DDL Source Z##_ASSOCIATION and copy the FROM clause and the field list to
the new DDL Source. If you did not complete the respective exercise, you can copy from
DDL Source S4D430_ASSOCIATION.
4. Perform a syntax check and activate your new DDL Source.
Define a CDS Extend View
Define a CDS Extend View for your CDS View Z##_Extended. Add the counter number and the
flight class to the element list. Add an association to table SPFLI and expose it in the field list.
1. In your own Package, create a new DDL Source (suggested name: Z##_Extension, where
## stands for your group number). Choose template extendView.
2. In the new DDL Source, provide a suitable name for the SQL View Append (suggested
name: Z##EXTENSION).
3. After key word EXTEND VIEW, enter the name of the CDS View you want to extend
(Z##_Extended).
4. In the element list, add fields CLASS and COUNTER from the original data source.
Hint:
Use the source code completion capabilities of the editor to choose from the
available fields.
© Copyright. All rights reserved.
197
Unit 4: Advanced Concepts
5. After the name of the Extend View in the WITH addition, add an association to table SPFLI.
Provide a suitable name for the association (suggested name: _connection) and specify
the join condition.
6. Expose the entire new association in the element list.
7. Perform a syntax check and activate your new DDL Source.
Check the View Extension
Open the definition of the extended view and analyze the extension. Open the extended view
in Data Preview and make sure that the additional fields and associations are displayed.
1. Open the definition of your CDS View Z##_Extended.
How can you see that this view has been extended?
2. Navigate from the extended view into the definition of the CDS Extend View.
3. Return to the extended view and open it with data preview.
4. Confirm that fields CLASS and COUNTER are there and that they are filled with data.
5. Confirm that association _Connection is there and that you can follow it in data preview.
198
© Copyright. All rights reserved.
Unit 4
Solution 14
Enhance a CDS View
Business Example
Template:
S4D430_ASSOCIATION (DDL Source)
Solution:
S4D430_EXTENDED (DDL Source)
S4D430_EXTENSION (DDL Source)
Create a Copy of the Template CDS View
Create a copy of your CDS View that exposes an association. If you did not complete the
respective exercise, you can copy from CDS View S4d430_Association.
1. In your own Package, create a new DDL Source (suggested name: Z##_Extended, where
## stands for your group number).
a) See the corresponding step in the previous exercise.
2. In the new DDL Source, provide a suitable name for the DB View (suggested name:
Z##EXTENDED).
a) See the corresponding step in the previous exercise.
3. Open your DDL Source Z##_ASSOCIATION and copy the FROM clause and the field list to
the new DDL Source. If you did not complete the respective exercise, you can copy from
DDL Source S4D430_ASSOCIATION.
a) See the corresponding step in the previous exercise.
4. Perform a syntax check and activate your new DDL Source.
a) See the corresponding step in the previous exercise.
Define a CDS Extend View
Define a CDS Extend View for your CDS View Z##_Extended. Add the counter number and the
flight class to the element list. Add an association to table SPFLI and expose it in the field list.
1. In your own Package, create a new DDL Source (suggested name: Z##_Extension, where
## stands for your group number). Choose template extendView.
a) See the corresponding steps in the previous exercise.
2. In the new DDL Source, provide a suitable name for the SQL View Append (suggested
name: Z##EXTENSION).
a) See source code extract from the model solution.
3. After key word EXTEND VIEW, enter the name of the CDS View you want to extend
(Z##_Extended).
a) See source code extract from the model solution.
© Copyright. All rights reserved.
199
Unit 4: Advanced Concepts
4. In the element list, add fields CLASS and COUNTER from the original data source.
Hint:
Use the source code completion capabilities of the editor to choose from the
available fields.
a) See source code extract from the model solution.
5. After the name of the Extend View in the WITH addition, add an association to table SPFLI.
Provide a suitable name for the association (suggested name: _connection) and specify
the join condition.
a) See source code extract from the model solution.
6. Expose the entire new association in the element list.
a) See source code extract from the model solution.
7. Perform a syntax check and activate your new DDL Source.
a) See the corresponding step in the previous exercise.
Check the View Extension
Open the definition of the extended view and analyze the extension. Open the extended view
in Data Preview and make sure that the additional fields and associations are displayed.
1. Open the definition of your CDS View Z##_Extended.
a) See the corresponding step in the previous exercise.
How can you see that this view has been extended?
There is a spiral - like (or snail - like) symbol next to the code line that contains the DEFINE
VIEW statement.
2. Navigate from the extended view into the definition of the CDS Extend View.
a) Click on the spiral-like (or snail-like) symbol next to the code line that contains the
DEFINE VIEW statement.
b) On the dialog box that appears, click on the name of the CDS Extend View.
3. Return to the extended view and open it with data preview.
a) Right-click anywhere in the DDL Source and choose Open With→ Data Preview.
4. Confirm that fields CLASS and COUNTER are there and that they are filled with data.
a) You should find the new fields on the far right of the data preview display.
Hint:
Not many bookings have a value in column COUNTER. You will need to
scroll down or might even have to apply a filter to see entries with a noninitial value in this column.
5. Confirm that association _Connection is there and that you can follow it in data preview.
a) Right-click on any line in the preview and choose Follow Assocation.
200
© Copyright. All rights reserved.
Lesson: Enhancing a CDS View
b) In the dialog window, click on associaton _Connection.
DDL Source S4D430_EXTENSION
@AbapCatalog.sqlViewAppendName: 'S4D430_EXTVIEW'
@EndUserText.label: 'Solution: View Extension'
extend view S4d430_Extended
with S4D430_Extension
association[1] to spfli as _connection
on b.carrid = _connection.carrid
and b.connid = _connection.connid
{
b.class,
b.counter,
_connection
}
© Copyright. All rights reserved.
201
Unit 4: Advanced Concepts
LESSON SUMMARY
You should now be able to:
202
●
Understand the Concept of CDS View Enhancements
●
Enhance a CDS View
© Copyright. All rights reserved.
Unit 4
Lesson 4
Linking a CDS View with Authorization Rules
LESSON OBJECTIVES
After completing this lesson, you will be able to:
●
Understand the Concept of CDS DCL
●
Create a DCL Source
Reminder - Classical Approach to Authorization Checks
,object Class ABC
Object Class XVZ
Authorization
X_6
Authorization
Profile
Role
User Master
Record
Figure 141: Reminder: Authorization Objects, Profiles, and Roles
In ABAP systems, all authorizations are based on a special repository object called
Authorization Object. Authorizations are defined in authorization profiles which are then
assigned to users.
Instead of defining and assigning authorization profiles directly, SAP recommends to define
and assign user roles (transaction PFCG) with generated authorization profiles.
Doing an authorization check means nothing else than looking up the user's master record to
see whether a given authorization is part of at least one of the authorization profiles assigned
to this user.
© Copyright. All rights reserved.
203
Unit 4: Advanced Concepts
Implicit Authorization Checks
• Performed by the ABAP Framework
- Start of a transaction
- Start of a Web Dynpro application
- Sia.rt of a report
- Call of a.n RFC function module
- Access to table content with data browser or maintenance dialogue
Explicit Authorization Checks
• Defined in theABAP Coding ,(AUTHORITY-CHECK stat.ement)
- Access to specific functionality
- Access to specific data
I
Figure 142: Reminder: Implicit and Explicit Authorization Checks
Some authorization checks are done implicitly by the ABAP framework when the user
accesses certain functionality (a transaction, an application, a report), or accesses data via
generic display and maintenance tools (SE16, SM30).
But most of the authorization checks are implemented in the ABAP coding, using ABAP
statement AUTHORITY-CHECK. Sometimes such explicit checks protect access to specific
functionality of the program (for example, switching from display to edit mode). In most
cases, they are related to data access.
The Need for Authorization Checks on Database Level
Ill
• General Problems;
- No visible link between data
ano authorization
objects
- Developer can forget (or ignore) necessary checks
Users with debugging rights can bypass authorization checks
• Problems related to Code-to-Data:
- All authorization checks on application level
- Some calculations cannot be done on the database because
they require an authorization check between steps
l
204
Figure 143: Known Problems of the Classical Approach
© Copyright. All rights reserved.
Lesson: Linking a CDS View with Authorization Rules
DATA gt_connections TYJ?E TABLE OF s4d430_access_control_a.
DATA gs_connection LIKE LINE OF gt_connections.
PARAMETERS pa_citfr TYPE s_from_cit DEFAULT 'FRANKFURT'.
SELECT FR:OM s4d430 access control a
FIELDS ca:r:rid, connid, cityfrom, cityto
WHERE cityfrom = @pa_citfr
INTO TABLE @gt�connections.
LOOP AT gt_connections INTO gs_connection.
Read all connections
departing from given city
Check Authorization for
each connection
AUTHORITY-CHECK OBJECT s CARR ID
ID 'CARRIO' FIELD gs_connection
I
ID I ACTVT
IF $y-subrc <> a .
r
I
FIELD ' 03
r •
DELETE gt_connections INDEX sy-tabix.
Remove connections from
the result set
ENDIF.
ENDLOOP.
I
Figure 144: Example: Classical Approach to Authorization Checks
The example shows a program that displays all flight connections departing from a given city.
To make sure the user does only see data for which he has display authorization, the program
does a loop aver the selection result set and removes the records for which the users lacks
authorization.
Note:
Of course, a more efficient solution would have been to order the result by field
carrid and to make sure that the authority check is only done once per carrier.
Repository Object DCL Source
DCL Source
ASAP Program
Define
Role ...
DDL Source
SELECT
FROM ...
CDS View
Figure 145: Access Control on Database – How It Works
© Copyright. All rights reserved.
205
Unit 4: Advanced Concepts
The figure shows the basic principle of CDS Access Control. A new repository object DCL
Source (or CDS Access Control) defines a CDS Role (key word DEFINE ROLE …). It relates the
CDS Role to one (or more) CDS Views (key word GRANT SELECT ON …) and defines access
conditions for this CDS View (key word WHERE …). Whenever an ABAP program accesses
this CDS View, the database interface will automatically filter the selection result according to
the access conditions.
Note:
CDS Access Control only works if the program accesses the CDS View directly.
Access Control is ignored if the CDS view is accessed indirectly over another CDS
view.
@EndUserText label: 'Demo: Authorization Check'
@MappingRole: true
define role S4d4�0_Role:_B
{
grant select
s
on -5--4-3-0--A-� -., -, e-_s_c_o_n_t_r_o�-B--·
wher,e carrid < > •AZ';
}
i;!1,
�rrid
AA
4!
<onnid
0017
26•-•c�,e,,e,t 0·1n:11
cityhom
tl!cWVO.RK
fonnid
<ityt<>
<it,M
0017
N£Wl'0Rt:
SAN !AANCISCO
SAN FAAr•U:IS....
NEW\i'ORX
NEWYO!'.X
FRANKRlRJ
SAN FRANCISCO
NFWVOR
AA
C064
SANFAAN01S. ..
l'{EwYO!tK
006,i
sa
sa
05>S
OWJ
ROM[
FRANt.FU!fi
TOi:VO
I\Z
07a9
TOl';VO
Kl.
Ol
Ol
0711(1
0105
1699
ROME
ROME
WM
0106
1699
1W
N:EWYOltK
N:EWVO.RK
FMNKfU�
SAN FRANCIS<:O
ROM[
<ityl1<1m
SAN FRANCISCO
NEWl'OIIX
'-AN,f!AiN('J<....,
flight connections
with carrid 'AZ'
removed from resul� set
=
Figure 146: Example: DLC Source
The example shows the data preview for two identical CDS Views (S4d320_Acess_Cotnrol_A
andS4d430_Access_Control_B). The only difference is a CDS Role related to one of them.
You can see that connections that do not match the access condition carrid <> 'AZ' are
suppressed from the result set of the second CDS View.
206
© Copyright. All rights reserved.
Lesson: Linking a CDS View with Authorization Rules
Create a New DCL Source
Right-Click the
Project
BCAOO
8C401
> EB
> Ill
00102
07SOA,';'/
DEVS41l4�0 (� l'lly
x
> 'I
) !fl HMOO
MAMIO_COLili8_DE
l'IDE7ll
)
> Efl
v !B WOECDS
.., Ill
Wl!ECDS,_OEIII
Co<1:D1tJ!
)
Diction:ary
)
)
IS
)
lliOlCOS_EXER
c .. ,.0..1.s..rv
Syst,mLibrory
57,JOl_mann•ll.m l>7>.
'il3JlllO_m•an<it..<n IY13, q'
0cre1e
Ocletc
R,m.,... from Contet
Cld•Alt•Shrfl•Down
,
rs
IP,ojca. ..
3
ABAP ftep,osilo<y l•tt---
.1
..
a,., ____ ,...,..._._,:;,
F •
,F<>ldu
GI ASAP Clm
lmpon...
l!,:porL.
Rd ......
FS
Clo.cPr<>j�
Ci
ABAP Function Groorp
ABf\P F"nctiw Mv,M<l
ABAP lnt...t•"'
Cl ABf\Pl'ro9r•m
Clo�Un..,l.alodProj..,..
Vafld•t�
THm
Com par• l'ol"nh
fltttorcfromlr>eill l-limary...
0
SQL(on..,lo
Olll!f.,
Cld•N
Figure 147: Create New DCL Source (1)
To create a new DDL Source, proceed as follows:
1. Right-click on your project in the Project Explorer.
•
2. Choose New→ ABAP Repository Object ….
r NtwASAPR!j>l><itoryObjoct
D
X
AIIAP R..,pr,�itg,y 01:ije,:,I
Ctc le �· ASAP �q,osiw,. Obje<l
L..
ProjKI:
_J
! i.QG,_el'Jo.monn•rt,.•n
typ•lilt!ft..t
e...;...,,
) '1b,
E:n�in«rin�
) �(l•l!ili<oliOM
Aoc>e!ll!II
)
1
C)
C111ntrol
Crul••,.A«�> Conlr<>1
)
froj«t: •
�-----------------� p�yg�·
Add� f
I KQG_IIOO.m•nn•rt.•n
l������������,J
!I.OM• pock 9"'
bk
Origimllangu•9" ._E_ N
_,
• l!a••
Figure 148: Create New DCL Source (2)
3. From the list, choose Core Data Services→ Access Control.
© Copyright. All rights reserved.
207
Unit 4: Advanced Concepts
1------1
0
Hint:
You can use the input field below Project to type a search term, e.g., access
4. Choose Next.
5. Enter the name of an (existing) package, and a name and description for the new DCL
Source.
Right-Click
Access Controls
under package
Q Add to fa,<>ril• �><f<ag:<!<
Nitm�··
-----==:]
Oc.(1[ptiOI\:"
Origin"11An91Ja9"' �E�N�==------------
C•nc;d
Figure 149: Shortcut (If Package Already Contains a DCL Source)
If your package already contains a SCL Source, you can use the following shortcut:
1. In the Project Explorer, expand subnode Core Data Services of the favorite package.
2. Right-click Access Control and choose New Data Definition.
208
© Copyright. All rights reserved.
Lesson: Linking a CDS View with Authorization Rules
CDS DCL Syntax
• Same Basiic Rules as for ABAP CDS DDL Syntax
- Case of key words and names
- Syntax ror I iterals, comments, statement delimiters
Key word DEFINE
is optional
• Statement DEFINE ROLE
I
[DEFINE] ROLE <role_name>
{
GRANT SELECT ON <cds_entityh WHERE c condto [AND I OR ccondz»]
[GRANT SELECT ON <cds_@ntity2> ••. ;]
One or more
GRANT statements
between .{" and ,,}"
At least one
condition per
GRANT statement
••• J
Delimiter .:" mandatory
after each
GRANT statement
Figure 150: ABAP CDS DCL Syntax
•
DCL Source name:
Max. 30 Characters
• Unique throughout the system (Customer namespace!)
• Always Upper-Case
CDS Ro11e name:
•
•
•
•
J
MaJ< 30 Characters
Unique throughout the system (Customer namespace!)
Not Oase-sensitlve
Can be different from DCL Source name (not recommendsdl)
Figure 151: Naming Rules and Recommendations
© Copyright. All rights reserved.
209
Unit 4: Advanced Concepts
Access Conditions in DCL Sources
• Literal Conditions
[
.. WHERE <field name>
=
<litel'al value>
- Use values specified litera.l ly to restrict access
- Allow declaration of new authorizations
PFCG conditions
... WHERE ( <fieldl>, <.field2>, ... )
=
aspect pfcg_auth( <authorization object>J
cauthor-rzat Ion field 1>,
<aLJthorization filed 2>,
- Evaluate authorizations in user master record
- Based on euthorizetion objects
- Fit into SAP authorization concept
]
Figure 152: Types of Conditions in DCL
The following ways of defining conditions in DCL exist:
Literal Conditions
Compare one field of the CDS View with a literal value.
PFCG Conditions
Use one or several fields of the CDS View to look up authorizations in the master record
of the current user.
One PFCG condition is always based on one authorization object.
The view fields on the left-hand side are assigned to the fields of the authorization object
on the right-hand side.
210
© Copyright. All rights reserved.
Lesson: Linking a CDS View with Authorization Rules
@EndUserText.label: 'Demo: Authorization Check With Link to User Profile'
@MappingRole: true
define role S4d43'0_Role_C
{ grant select
on S4d430_Access_control_c
where (carrid)
= aspect pfcg_auth( s_CARRID,
CARRID,
ACTVT
=
and (carrid_. counter)
'03'
aspect pfcg_auth( S_COUNlER,
CARRIO,
COUNTNUMJ
ACTVT "' '03'
)J
}
Left-hand side:
One or more corrma-sepsrated
view fields in brackets
Right-hand sid:e:
Key word ASPECT and
function pfcg_auth( )
Arguments of pfcg_auth:
One authorization object
with its fields
Figure 153: Example: PFCG Conditions
The CDS role in the example above contains two PFCG conditions.
The first condition is based on authorization object S_CARRID. In ABAP, the corresponding
AUTHORITY-CHECK statement would look like this:
AUTHORITY-CHECK OBJECT 'S_CARRID'
ID 'CARRID' FIELD view-carrid
ID 'ACTVT' FIELD '03'.
The second condition is based on authority object S_COUNTER. This authorization object has
three authorization fields: CARRID, COUNTNUM and ACTVT. The corresponding
AUTHORITY-CHECK statement would look like this:
AUTHORITY-CHECK OBJECT
'S_COUNTER'
ID 'CARRID' FIELD view-carrid
ID 'COUNTNUM' FIELD view-counter
ID 'ACTVT' FIELD '03'.
© Copyright. All rights reserved.
211
Unit 4: Advanced Concepts
Template defineInstanceRole
D
x
Templnte1ii
�lect ,i.ne of titt fVJil41:,lc 1i.npl1lfl.
Dumtln.tanc•
flol�I
Ddino la<taru:o Role wilh lnh,mance
Defino Unres1,i�od Aec,,u Ro'le
'Deline ACCfl$ lnh;�.._;,g Rolt
-ndUserloxt.lab<l: "S{d<l_sourc•_description} •
(IMoppl.ngRol.,: truo
dofin" r<>Jc S{dcl,_sQo.-.:e_•_l {
gl"
.t
SIC'J!it:ct
S{Cd$_<"tily}
ll!lltc:r,ic
S(c<>ndition)J
< l!o<t.
..i_,__
__
�
Ca.ni::el
Figure 154: Template Define Instance Role
Several templates exist for creating DCL sources.
I»
Note:
In customer development systems, currently only template DefineInstaceRole is supported.
Authorization-related Annotations
Ill
Annotations in DCL Sources
@EndUserText.label:
- Translatable short text for role (same as in DDL Sources)
@Mappi ngRole:
- Value true:
Role is implicitly assigned to an users
- Value false: Currently not supported by ABAP CDS
Annotations in DDL Sources
• @AccessControl .authorizationCheck:
- #CHECK:
Perform authorization check. Syntax warning if no role is assigned
- #NOT_RE®IRED: Like #CHECK but suppress syntax warning
- INOT_ALLOOED: No authorization check. Syntax warning if role is assigned
I
212
Figure 155: Authorization-related Annotations
© Copyright. All rights reserved.
Unit 4
Exercise 15
Create and Use a DCL Source
Business Example
Template:
S4D430_ASSOCIATION (DDL Source)
Solution:
S4D430_AUTHORIZATION (DDL Source)
S4D430_ACCESS_CONTROL (DCL Source)
Create a Copy of the Template CDS View
Create a copy of your CDS View that exposes an association. If you did not complete the
respective exercise, you can copy from CDS View S4d430_Association.
1. In your own Package, create a new DDL Source (suggested name: Z##_Authorization,
where ## stands for your group number).
2. In the new DDL Source, provide a suitable name for the DB View (suggested name:
Z##AUTH).
3. Open your DDL Source Z##_ASSOCIATION and copy the FROM clause and the field list to
the new DDL Source. If you did not complete the respective exercise, you can copy from
DDL Source S4D430_ASSOCIATION.
4. Perform a syntax check and activate your new DDL Source.
Define A CDS Role
Define a CDS Role for your CDS View Z##_Authorization. Make sure only bookings of those
airlines are selected for which the user got reading authorization.
1. In your own Package, create a new DCL Source (suggested name: Z##_Access_Control,
where ## stands for your group number). Choose template DefineMappingRole.
2. Edit the new DCL Source. After key word DEFINE ROLE, enter a name for the CDS Role.
Hint:
It is recommended to use the same name for the DCL Source and the CDS
Role (apart from capitalization). Therefore, the recommended name for the
rule is Z##_Access_Control.
3. After key word GRANT SELECT ON, enter the name of the CDS View you want to link with
authorization rules (Z##_Authority).
4. After key word WHERE, enter the name of column CARRID in brackets.
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213
Unit 4: Advanced Concepts
5. Provide input for function aspect_pfcg_auth. First, enter the name of the authorization
object, then the name of the authorization field that should be supplied with view field
CARRID. The final argument for function aspect_pfcg_auth should be condition ACTVT =
'03'.
10
Hint:
The correct authorization object is S_CARRID.
6. Perform a syntax check and activate your new DCL Source.
Check the Authorization
Open the definition of the view for which you just defined a CDS Role. Open the Data Preview
and make sure that only the data is displayed for which your user is authorized.
1. Open the definition of your CDS View Z##_Authorization.
Where can you see that there is a CDS role assigned to this CDS View?
2. Open the CDS View with data preview.
3. Confirm that the result does not contain bookings for which your user does not have
display authorization.
Hint:
Your user should not have display authorization for carrier UA.
4. Confirm that association _Connection is there and that you can follow it in data preview.
214
© Copyright. All rights reserved.
Unit 4
Solution 15
Create and Use a DCL Source
Business Example
Template:
S4D430_ASSOCIATION (DDL Source)
Solution:
S4D430_AUTHORIZATION (DDL Source)
S4D430_ACCESS_CONTROL (DCL Source)
Create a Copy of the Template CDS View
Create a copy of your CDS View that exposes an association. If you did not complete the
respective exercise, you can copy from CDS View S4d430_Association.
1. In your own Package, create a new DDL Source (suggested name: Z##_Authorization,
where ## stands for your group number).
a) See the corresponding step in the previous exercise.
2. In the new DDL Source, provide a suitable name for the DB View (suggested name:
Z##AUTH).
a) See the corresponding step in the previous exercise.
3. Open your DDL Source Z##_ASSOCIATION and copy the FROM clause and the field list to
the new DDL Source. If you did not complete the respective exercise, you can copy from
DDL Source S4D430_ASSOCIATION.
a) See the corresponding step in the previous exercise.
4. Perform a syntax check and activate your new DDL Source.
a) See the corresponding step in the previous exercise.
Define A CDS Role
Define a CDS Role for your CDS View Z##_Authorization. Make sure only bookings of those
airlines are selected for which the user got reading authorization.
1. In your own Package, create a new DCL Source (suggested name: Z##_Access_Control,
where ## stands for your group number). Choose template DefineMappingRole.
a) In the ABAP perspective of Eclipse, right-click on your project and choose New
→ Other ABAP Repository Object.
b) On the next window, choose Core Data Services→
DCL Source.
c) Enter the name of your package, a name, and a short description for the new object
and choose Next.
d) If the tool asks for a template, select DefineMappingRole and choose Next.
© Copyright. All rights reserved.
215
Unit 4: Advanced Concepts
e) Assign the object to your transport request and choose Finish.
2. Edit the new DCL Source. After key word DEFINE ROLE, enter a name for the CDS Role.
Hint:
It is recommended to use the same name for the DCL Source and the CDS
Role (apart from capitalization). Therefore, the recommended name for the
rule is Z##_Access_Control.
3. After key word GRANT SELECT ON, enter the name of the CDS View you want to link with
authorization rules (Z##_Authority).
a) See source code extract from the model solution.
4. After key word WHERE, enter the name of column CARRID in brackets.
a) See source code extract from the model solution.
5. Provide input for function aspect_pfcg_auth. First, enter the name of the authorization
object, then the name of the authorization field that should be supplied with view field
CARRID. The final argument for function aspect_pfcg_auth should be condition ACTVT =
'03'.
10
Hint:
The correct authorization object is S_CARRID.
a) See source code extract from the model solution.
6. Perform a syntax check and activate your new DCL Source.
a) See the corresponding step in the previous exercise.
Check the Authorization
Open the definition of the view for which you just defined a CDS Role. Open the Data Preview
and make sure that only the data is displayed for which your user is authorized.
1. Open the definition of your CDS View Z##_Authorization.
a) See the corresponding step in the previous exercise.
Where can you see that there is a CDS role assigned to this CDS View?
On the problems tab below the editor. there is a corresponding message in node Infos.
2. Open the CDS View with data preview.
a) Right-click anywhere in the DDL Source and choose Open With→ Data Preview.
3. Confirm that the result does not contain bookings for which your user does not have
display authorization.
10
216
Hint:
Your user should not have display authorization for carrier UA.
© Copyright. All rights reserved.
Lesson: Linking a CDS View with Authorization Rules
a) Sort the result by field CARRID and scroll down.
b) Alternatively, you can right-click on column CARRID and choose Distinct Values for
[carrid].
4. Confirm that association _Connection is there and that you can follow it in data preview.
a) Right-click on any line in the preview and choose Follow Assocation.
b) In the dialog window, click on associaton _Connection.
DCL Source S4D430_ACCESS_CONTROL
@EndUserText.label: 'Solution: Role for View S4d430_Authorization'
@MappingRole: true
define role S4d430_Access_Control
{ grant select
on S4d430_authorization
where ( CARRID ) = aspect pfcg_auth( S_CARRID,
CARRID,
ACTVT = '03'
);
}
© Copyright. All rights reserved.
217
Unit 4: Advanced Concepts
LESSON SUMMARY
You should now be able to:
218
●
Understand the Concept of CDS DCL
●
Create a DCL Source
© Copyright. All rights reserved.
UNIT 5
Database-Specific Features of
ABAP CDS
Lesson 1
Understanding CDS Table Functions
Exercise 16: Define and Use a CDS Table Function
220
231
UNIT OBJECTIVES
●
Understand the AMDP Framework
●
Define CDS Table Functions
●
Read Data From CDS Table Functions
© Copyright. All rights reserved.
219
Unit 5
Lesson 1
Understanding CDS Table Functions
LESSON OBJECTIVES
After completing this lesson, you will be able to:
●
Understand the AMDP Framework
●
Define CDS Table Functions
●
Read Data From CDS Table Functions
Basic Features of AMDP
Almost every database supports database procedures. Such procedures are stored and
executed on the database. The implementation is usually written in a scripting language that
is highly database-specific.
As of release 7.40 SP05, ABAP supports database procedures that are stored in the ABAP
repository and transported with standard ABAP transport requests. This technique is known
as ABAP-Managed Database Procedures (AMDP).
Ill
ASAP Program
By
Database
Procedure
Stored Procedure
on Database
Figure 156: Basic idea of ABAP Managed Database Procedures
The basic idea of AMDP is the following:
The database procedure is defined and implemented as a method of a global class. The
implementation of such a method consists of database-specific script that can only be
executed on the database but not on the ABAP stack.
220
© Copyright. All rights reserved.
Lesson: Understanding CDS Table Functions
The AMDP framework creates a stored procedure on the database and redirects (or
forwards) any call of the AMDP method to this stored procedure.
CLASS cl_s4d430-amdp:._..dem.o IMPLEMENTATION.
METHOD procedure BY OA:TABASE PROCEDURE
FOR HDB LANGUAcGE. SQLSCRIP'I'
OPTIONS READ-ONLY
USING scustom.
et_normal
se].e,ct id, name
from scustom
where mandt
=
:iv mandt and name
:iv_name;
select id, name
from scustom
where mandt = :iv_mandt
and contains( name,
:iv_name, fuzz.y)
order by score() .-tesc;
ENDMBTROD.
ENDCLAS,S.
contains() and score(} are
SAP HANA specific functions
(not available in Open S.QL
or CDS DOL)
Figure 157: Example: Implementation of an AMDP Method
This example shows the implementation of an AMDP method.
Although the class is an ABAP repository object, the source code between METHOD and
ENDMETHOD is not ABAP.
The two statements are written in SQL Script as it is understood by SAP HANA database.
Note:
Although there is a lot of common ground between the syntax ABAP CDS DDL and
SAP HANA SQL Script, you must not mistake the two.
The following additions are needed in ABAP statement METHOD:
FOR
Specifies the database on which the AMDP can run. In the example, HDB stands for SAP
HANA database. This is currently the only supported value.
LANGUAGE
Specifies the language of the implementation. In the example, it is SQL Script. This is
currently the only value available to customers
USING
Is required if the method implementation uses objects from the ABAP Dictionary.
Transparent tables and Dictionary Views are supported. CDS View names are not
supported, here. If you want to use a CDS View in an AMDP, you have to access the
corresponding CDS SQL View.
OPTIONS
Is intended for additional settings. Currently READ-ONLY is the only supported option.
© Copyright. All rights reserved.
221
Unit 5: Database-Specific Features of ABAP CDS
I
Cl.A$$ cl_s4d430_amdp:._demo OEFlNI'fION.
Implementation of this
in,terfaoe mandatory
PUBLIC SECTION.
INTERFACES if_amdp_marker_hdb.
TYPES ty_t_customers TYPE STANDARD TABLE OF ....
CLASS-METHODS procedure
Parameters passed by value
1
IMP 0RTING
VALQE(iv_name)
VALUE (iv_mandt)
:EXF 0RTING
TYPE s_custnanie DEFAULT 'Sc:hwarz'
'l'YPE mandt
1
VALUE(et_normal) TYPE ty_t_customers
VALUE(et_fuzzy) TYPE ty_t_customers.
,
J
ENDCLAS.S .
Figure 158: Example: Definition of an AMDP Method
This slide shows the definition of an AMDP class. Implementation of interface
IF_AMDP_MARKER_HDB is mandatory.
The parameters of the AMDP method have to be passed by value, and the parameter types
need to be elementary types or table types. Structure types are not allowed.
Ill
1
• Class D efi nit ion
- Implementation of Interface IF_AMDP_MARKER_HDB
• Method Definition
- VALUE() addition for all parameters
Only scalar or table types for parameters (no structures)
• Supported Databases and Languages
Only SAP HANA (at present)
Only SAP HANA SQL Script (at present)
• Use of Dictionary Object.s
- Transparent Tables and Dictionary Views
- CDS Views only via their CDS SOL Views
- Need to be listed after USING
l
Figure 159: Prerequisites and Limitations
AMDP Functions
As of release 7.50, the AMDP framework supports AMDP functions alongside the existing
AMDP procedures.
222
© Copyright. All rights reserved.
Lesson: Understanding CDS Table Functions
Global
ASAP Class
ASAP Program
Method with
Function script
By
By
Database
Procedure
Database
!Function
il··:.� m1
•.1�.n 112 l.:l-11s1·'•we•
:
.
,.,
on Database
Ill
p
Figure 160: AMDP Functions
AMDP functions use the new addition BY DATABASE FUNCTION of the METHOD statement in
AMDP classes.
Unlike AMDP procedure implementations, AMDP function implementations have no export or
changing parameters. They have exactly one tabular return value.
AMDP function implementations cannot be called by an ABAP program directly. But they can
be called from other AMDP functions or procedures.
CLASS c;1_s4d430_amdp_demo DEFINITION.
Same pre-requisites
PUBLIC SECTION.
as for AMDP procedures
INTERFACES if_amdp_marker_hdb.
TYPES ty_t_customers T'YPE STAND.ARD T'ABLE OF ...•
Thii s method cannot
be called in ABAP
1
CLASS-METHODS £unction
IMPORTING
VALtJE(iv_na.me}
VALUE (iv_mandt)
TYPE s c.ustname DEFAULT ' Schwarz '
TYPE ma.ndt
RETURNING
VALCJE(et_customers) TYPE ty_t_customers.
ENDCLASS.
Exactly one returning
parameter
Figure 161: Example: Definition of an AMDP Function
This slide shows the definition of an AMDP class . AMDP method FUNCTION is intended to be
implemented by a database function. It is defined as a functional method, i.e., it has exactly
one tabular returning parameter and besides that only import parameter.
© Copyright. All rights reserved.
223
Unit 5: Database-Specific Features of ABAP CDS
Note:
Once this functional method is implemented by a database function, you cannot
call it in ABAP any more.
CLASS cl_s4d430_amdp_demo IMPLEMENTATION.
METHOD function BY DATABASE FUNCTION
FOR. HDB LANGUAGE SQLSCRIPT
OPTIONIS READ-ONLY
USIN:G scustom.
Return value is a table with
return select id, name
from scustom
columns ID and NAME
where mandt = :iv_mandt
a1nd contains( na1me, :iv_name, fuzzy )
order by score() desc;
ENDMETHOD,
ENDCLASS.
I
Figure 162: Example: Implementation of an AMDP Function
This example shows the implementation of an AMDP function.
Addition BY DATABASE FUNCTION is used Instead of BY DATABASE PROCEDURE. The
remaining additions have the same meaning and values as for database procedures.
In the script for a database function, statement RETURN is mandatory. The RETURN
statement defines the values for the return parameter.
AMDP Functions for CDS Table Functions
AMDP functions are functional methods of global classes which define functions stored and
executed on the database. It is not allowed to call functional methods that define AMDP
functions directly in ABAP.
ABAP CDS introduced CDS table functions to make AMDP functions available as data sources
of SELECT statements.
224
© Copyright. All rights reserved.
Lesson: Understanding CDS Table Functions
ABAP Program
DDL Source
Global
ABAP Class
D·efine
Table
Function ...
By
Database
Function
CDS Table
Function
Figure 163: The Basic Idea of CDS Table Functions
The basic idea of CDS table functions is illustrated in the figure above:
A CDS table function is defined in a DDL source via key word DEFINE TABLE FUNCTION. (Just
like CDS Views are defined in DDL Sources via key word DEFINE VIEW.)
The definition of the CDS table function refers to an existing AMDP function via addition
IMPLEMENTED BY.
An ABAP program (or a CDS View) can use the CDS table function as data source in the from
clause of a SELECT statement – just like it would do with a CDS View, database view, or
transparent table.
•
The CDS framework executes the SELECT from the CDS table function by calling the assigned
function on the database.
@EndUserText.label: 'Demo: Table Function'
define table function S4d430_Table_Function
with par-emeter s
name_in
s_ custname
Parameters are passed
to import parameters
of AMDP function
returns {
mandt
id
name
mandt;
s_customer;
s; custname;
Field list of table function
(= line type of AMDP
function's return value
implemented by m.ethod CL_S4!0430_AMDP_FOR_CDS=>FOR_TABLE_FUNC;
_J
Niame of AMDP class
and AMDP methrod
Figure 164: Example: Definition of a CDS Table Function
© Copyright. All rights reserved.
225
Unit 5: Database-Specific Features of ABAP CDS
The example shows the definition of a CDS table function. From the outside, it looks like the
definition of a CDS View with an input parameter name_in and an element list with the three
fields mandt, id, and name.
I
CLASS cl s4d430_amdp_for_cds DEFINITION.
PUBLIC SECTION.
INTERFACES if_amdp_marker hdb.
TYPES ty_t_customers TYPE STANDARD TABLE OF ....
No parameter definiition siqnature is taken fr-om
CDS table function
CLASS-METHODS for - table - func
FOR TABLE FUNCTION s4d430_table_function.
ENDCLASS.
I
Figure 165: Example: Definition of an AMDP Function for CDS
An AMDP method that implements a CDS table function is defined without parameters.
Instead, addition FOR TABLE FUNCTION … is used. The signature of the AMDP method is
then taken from the CDS table function.
Template defineTableFunctionWithParameters
r New D�t, Oefi:nition
x
D
TeJnpla:tes
I
s.l•ct one aHho •voilablttomp.1at.,,.
Defino ti\;; type si,gnatu,c ..1 ,11 dimt dcF)tlndtnt COS ubtc
function with impaotin� parameters. Thehbl•lundian i,
impl@mi!nt� in the sped li!d AA.AP method\.
The lib! funcliesn can be used in Op.ff> SOL !nd ,s, data
IOUfC�il'I oth� ,;ic,;, clefi11ition1.
@,EndUserTe,c't. labd: '•S{ddl_sourc•_de,cripticn} ·
d.,fine ta.hle function $,{ddl_sourc•_na=_.,ditabll!}
witt> para.eters Hl'arca !!'ter_n• e} : $(pora=<eter_typ.e}
relUl'IIS {
S{clielllt_de«nt_n
} : "b"P'· chit;
S,{el, nt_na ,) ; S(el,o:e;it_typ,};
i{.:o,t�(lr'}
<
11
ck
c ncel
Figure 166: Template Define Table Function with Parameters
When creating a new DDL Source for a CDS Table function, you are supported by a dedicated
template.
226
© Copyright. All rights reserved.
Lesson: Understanding CDS Table Functions
Creating a CDS Table Function
When developing a CDS table function, it is most important to do it in the right order.
• Create DDL Source for CDS Table Function
- Use Template DefineTableFunctionWithParameters
- Define parameters (optional) and return value (don't forget the client field!)
- Leave the information after IMPLEMENTED BY as it is (not checked by syntax
check)
- Activate the DDL Source
• Create AMDP Class With AMDP Method
- Create a global class and implement interface IF_AMDP_MARKER_HDB
- Define a public static method with addition FOR TABLE FUNCTION .
- Implement the method as an AMDP function
- Activate the global class
Complete the Definition of the CDS Table Function
- Enter the AMDP class and AMDP method after IMPLEMENTED BY
- Activate the DDL Source
- Test the CDS table function in data preview
Figure 167: CDS Table Function: Recommended Sequence
You have to create and activate the DDL Source first!
This is because you need the existing, activated CDS Table Function when you define the
AMDP method with addition FOR TABLE FUNCTION.
On the other hand, it is no problem to activate the DDL Source before the AMDP method. The
syntax check accepts a non-existent class and/or method after IMPLEMENTED BY.
Once you finished implementing the AMDP function, return to your CDS table function
definition and update the name of the AMDP class and the AMDP method.
© Copyright. All rights reserved.
227
Unit 5: Database-Specific Features of ABAP CDS
CDS Table Functions in Open SQL
Use CDS Table function like any other CDS Views
DATA gt_data, TYPE TABLE OF s4d430_table_function.
PARAMETERS pa_nam lYP'E s_custname LOWER CASE D1EFAULT
SELECT FIROM s4d430_table_function( name_in
FIELDS id, name
INTO TAIBLE @gt_data.
=
'.Schwarz'.
@pa_nam
Possible runtime error if AMDP not supported on current system:
Cate9ory
Rum;.i.De Error:,
ASAP pr::Qil'r�n� error
SAPSgL_UHSUPPOR!ED_FD.!UR[
Exce_pt.
ASAP P'rogram
CX_SY_SJ2L_UNSOE'PORTED_E'UJ1JR.[
S4D430_USE_!AB:LE:_roNC!ION
Applicu:.1011 Componenr:
one anci JUie
CA
28.cn.2011 14:3!1:U
I
IShor,;
tex,:
Ull:!UPJX>lC1ll!d dai:ab.tsl!: exr.l!:l'.LII ea,
J
Figure 168: Use of CDS Table Function in Open SQL
In Open SQL, you can use CDS table functions like any other CDS View. But you have to be
aware that the underlying AMDP functions are not supported by all databases. (Actually, they
are only supported by SAP HANA at present.)
If a CDS table function is accessed in a system that does not support this feature, a runtime
error occurs. You can catch this runtime error via exception class
CX_SY_SQL_UNSUPPORTED_FEATURE.
Syntax check issues a warning (direct or indirect use of AMDP!)
l
i
The database feature "AMDP _TABLE_FUNCTION" is used here (read the long text).
Check system capability and provide alternative coding
'
DATA gt_feature_set: TYPE cl_:aba:p_dbfeatures=>features....;set_t.
INSERT cl_abap_dhfeatures=>amdp_table_functions
INTO TABLE gt_feature_set.
IF cl_abap_dbfeatures=>use_features( gt_feature_set)
=
abap_false.
ENDIF.
]
Figure 169: Check of System Capabilities Needed
To make you aware of this risk, ABAP syntax check issues a warning wherever a program
accesses a CDS table function. These warnings are not restricted to direct use of the table
function. If you access an ordinary CDS View that uses the table function as its data source,
the system issues the same warning.
228
© Copyright. All rights reserved.
Lesson: Understanding CDS Table Functions
If there is the slightest chance that your coding might run on systems that do not support
AMDP functions, use the service method of class CL_ABAP_DBFEATURES to check the
systems capability. If it doesn't, stop program execution or provide an alternative coding.
© Copyright. All rights reserved.
229
Unit 5: Database-Specific Features of ABAP CDS
230
© Copyright. All rights reserved.
Unit 5
Exercise 16
Define and Use a CDS Table Function
Business Example
Template:
CL_TABLE_FUNC_T1 (Global Class)
S4D430_TABLE_FUNC_T1 (Executable Program)
Solution:
CL_TABLE_FUNC_S1 (Global Class)
S4D430_Customer_Fuzzy (DDL Source)
S4D430_TABLE_FUNC_S1 (Executable Program)
Copy Template Class with Dummy Method
Create a copy of template class CL_TABLE_FUNCTION_S1 and activate it.
1. In your own Package, create a copy of global class S4D430_TABLE_FUNC_T1 (suggested
name: ZCL_##_TABLE_FUNC, where ## stands for your group number).
Hint:
If you want to perform this step in ADT, right click the global class and choose
Duplicate.
2. Activate the new global class.
Define a CDS Table Function
Define a CDS Table Function that imports a customer name and returns a list of customer
data.
1. In your own Package, create a new DDL Source (suggested name: Z##_Customer_Fuzzy,
where ## stands for your group number). Choose template
defineTableFunctionWithParameters.
2. In the new DDL Source, define an input parameter of type S_CUSTNAME (suggested
name: NAME_IN).
3. Within the curly brackets after key word RETURNS, enter a list of customer data that
should be returned by the table function. This list should include the client, the customer
id, the customer name, the city, and the country. Make sure to use delimiter “;” after each
return field (including the last!).
© Copyright. All rights reserved.
231
Unit 5: Database-Specific Features of ABAP CDS
Hint:
You can look up appropriate data elements in the definition of database table
SCUSTOM.
4. After key work IMPLEMENTED BY METHOD, specify the name of your global class and the
name of the dummy method in this class.
Hint:
You can use the source code completion capabilities of the editor to enter
this information.
5. Perform a syntax check and activate your new DDL Source.
Implement the AMDP Method for the CDS Table Function
In your global class, define and implement an AMDP method by decommenting the method
implementation. Connect this AMDP Method to your CDS Table Function.
1. Edit your global class. Go to the implementation of method customer_fuzzy. Remove the
full stop after the method name and decomment the additions BY DATABASE
PROCEDURE ... USING SCUSTOM..
2. Perform a syntax check.
What does the syntax error say?
3. Adjust the method definition. Do not add parameters, directly. Use addition FOR TABLE
FUNCTION instead and add the name of your CDS Table function. The method then takes
over the import parameter(s) and the structure of the returning parameter from the CDS
Table Function.
4. Perform another syntax check.
What does the next syntax error say?
5. In the global section of the class definition, add interface IF_AMD_MARKER_HDB.
6. Complete the implementation by decommenting the SQL script coding in the AMDP
method.
7. Activate your global class.
Access CDS Table Function with Open SQL
Create a copy of executable program S4D430_TABLE_FUNC_T1. In the FROM clause of the
SELECT statement, replace transparent table SCUSTOM with your CDS Table Function.
232
© Copyright. All rights reserved.
Lesson: Understanding CDS Table Functions
Optionally, add coding that checks whether the current database supports CDS Table
functions; and if it doesn’t, issue an error message.
1. Create a copy of executable program S4D430_TABLE_FUNC_T1 (suggested name of the
copy: Z##_TABLE_FUNC, where ## stands for your group number).
Hint:
If you want to perform this step in ABAP Development Tools, choose
Duplicate from the context menu.
2. In the From clause of the SELECT statement, remove transparent table SCUSTOM and
replace it with your CDS Table Function Z##_Customer_Fuzzy.
I»
Note:
Don’t forget to supply an actual value for the table function’s input parameter.
3. Execute a syntax check.
Why do you get a warning from syntax check?
4. Optional: Before the select statement, implement a call of static method use_features of
global class CL ABAP DBFEATURES. If table functions are not supported in this system,
issue an error message, e.g., message 030 of message class S4D430.
5. Activate and test your program.
© Copyright. All rights reserved.
233
Unit 5
Solution 16
Define and Use a CDS Table Function
Business Example
Template:
CL_TABLE_FUNC_T1 (Global Class)
S4D430_TABLE_FUNC_T1 (Executable Program)
Solution:
CL_TABLE_FUNC_S1 (Global Class)
S4D430_Customer_Fuzzy (DDL Source)
S4D430_TABLE_FUNC_S1 (Executable Program)
Copy Template Class with Dummy Method
Create a copy of template class CL_TABLE_FUNCTION_S1 and activate it.
1. In your own Package, create a copy of global class S4D430_TABLE_FUNC_T1 (suggested
name: ZCL_##_TABLE_FUNC, where ## stands for your group number).
Hint:
If you want to perform this step in ADT, right click the global class and choose
Duplicate.
a) See the corresponding step in previous exercises.
2. Activate the new global class.
a) See the corresponding step in previous exercises.
Define a CDS Table Function
Define a CDS Table Function that imports a customer name and returns a list of customer
data.
1. In your own Package, create a new DDL Source (suggested name: Z##_Customer_Fuzzy,
where ## stands for your group number). Choose template
defineTableFunctionWithParameters.
a) See the corresponding steps in the previous exercise.
2. In the new DDL Source, define an input parameter of type S_CUSTNAME (suggested
name: NAME_IN).
a) See source code extract from the model solution.
3. Within the curly brackets after key word RETURNS, enter a list of customer data that
should be returned by the table function. This list should include the client, the customer
id, the customer name, the city, and the country. Make sure to use delimiter “;” after each
return field (including the last!).
234
© Copyright. All rights reserved.
Lesson: Understanding CDS Table Functions
Hint:
You can look up appropriate data elements in the definition of database table
SCUSTOM.
a) See source code extract from the model solution.
4. After key work IMPLEMENTED BY METHOD, specify the name of your global class and the
name of the dummy method in this class.
Hint:
You can use the source code completion capabilities of the editor to enter
this information.
a) See source code extract from the model solution.
5. Perform a syntax check and activate your new DDL Source.
a) See the corresponding step in the previous exercise.
DCDL Source S4d430_Customer_Fuzzy
@EndUserText.label: 'Solution: Table Function'
define table function S4D430_Customer_Fuzzy
with parameters name_in : s_custname
returns {
mandt : mandt;
id : s_customer;
name : s_custname;
city : s_city;
country : country;}
implemented by method CL_S4D430_TABLE_FUNC_S1=>CUSTOMER_FUZZY;
Implement the AMDP Method for the CDS Table Function
In your global class, define and implement an AMDP method by decommenting the method
implementation. Connect this AMDP Method to your CDS Table Function.
1. Edit your global class. Go to the implementation of method customer_fuzzy. Remove the
full stop after the method name and decomment the additions BY DATABASE
PROCEDURE ... USING SCUSTOM..
a) See source code extract from the model solution.
2. Perform a syntax check.
a) See relevant steps in previous exercises.
What does the syntax error say?
The method ... contains a database function. but there is no RETURNING parameter
defined.
3. Adjust the method definition. Do not add parameters, directly. Use addition FOR TABLE
FUNCTION instead and add the name of your CDS Table function. The method then takes
over the import parameter(s) and the structure of the returning parameter from the CDS
Table Function.
© Copyright. All rights reserved.
235
Unit 5: Database-Specific Features of ABAP CDS
a) See source code extract from the model solution.
4. Perform another syntax check.
a) See relevant steps in previous exercises.
What does the next syntax error say?
Database procedures managed by ABAP can only be defined in classes that implement
the marker interface "IF_AMDP_MARKER_HDB".
5. In the global section of the class definition, add interface IF_AMD_MARKER_HDB.
a) See source code extract from the model solution.
6. Complete the implementation by decommenting the SQL script coding in the AMDP
method.
a) See source code extract from the model solution.
7. Activate your global class.
a) See the relevant steps in previous exercises.
Global Class CL_S4D430_TABLE_FUNC_S1
CLASS cl_s4d430_table_func_s1 DEFINITION PUBLIC FINAL CREATE PUBLIC .
PUBLIC SECTION.
INTERFACES if_amdp_marker_hdb.
CLASS-METHODS customer_fuzzy FOR TABLE FUNCTION
s4d430_customer_fuzzy.
ENDCLASS.
CLASS cl_s4d430_table_func_s1 IMPLEMENTATION.
METHOD customer_fuzzy BY DATABASE FUNCTION
FOR HDB LANGUAGE SQLSCRIPT
OPTIONS READ-ONLY
USING scustom.
RETURN SELECT mandt, id, name, city, country
FROM scustom
WHERE contains( name, :name_in, fuzzy )
ORDER BY score( ) desc;
ENDMETHOD.
ENDCLASS.
Access CDS Table Function with Open SQL
Create a copy of executable program S4D430_TABLE_FUNC_T1. In the FROM clause of the
SELECT statement, replace transparent table SCUSTOM with your CDS Table Function.
Optionally, add coding that checks whether the current database supports CDS Table
functions; and if it doesn’t, issue an error message.
1. Create a copy of executable program S4D430_TABLE_FUNC_T1 (suggested name of the
copy: Z##_TABLE_FUNC, where ## stands for your group number).
236
© Copyright. All rights reserved.
Lesson: Understanding CDS Table Functions
Hint:
If you want to perform this step in ABAP Development Tools, choose
Duplicate from the context menu.
a) See relevant steps in previous exercises.
2. In the From clause of the SELECT statement, remove transparent table SCUSTOM and
replace it with your CDS Table Function Z##_Customer_Fuzzy.
I»
Note:
Don’t forget to supply an actual value for the table function’s input parameter.
a) See source code extract from the model solution.
3. Execute a syntax check.
Why do you get a warning from syntax check?
Because table functions are not supported by all database systems. you need to check
before this SELECT statement. that it is supported n the current system.
a) See relevant steps in previous exercises.
4. Optional: Before the select statement, implement a call of static method use_features of
global class CL ABAP DBFEATURES. If table functions are not supported in this system,
issue an error message, e.g., message 030 of message class S4D430.
a) See source code extract from the model solution.
5. Activate and test your program.
a) See relevant steps in previous exercises.
*&--------------------------------------------------------------------*
*& Report s4d430_asso_s1
*&--------------------------------------------------------------------*
*&
*&--------------------------------------------------------------------*
REPORT s4d430_table_func_s1.
TYPES: BEGIN OF ty_s_customer,
id TYPE Scustom-id,
name TYPE scustom-name,
city TYPE scustom-city,
country TYPE scustom-country,
END OF ty_s_customer.
TYPES ty_t_customers TYPE STANDARD TABLE OF ty_s_customer
WITH NON-UNIQUE KEY id.
DATA gt_customers TYPE ty_t_customers.
© Copyright. All rights reserved.
237
Unit 5: Database-Specific Features of ABAP CDS
* ALV Processing
DATA go_salv TYPE REF TO cl_salv_table.
DATA gx_excp TYPE REF TO cx_salv_error.
* Selection Screen
PARAMETERS pa_nam TYPE s_custname DEFAULT 'Schwarz' LOWER CASE.
* Check db feature
DATA gt_feature_set TYPE cl_abap_dbfeatures=>features_set_t.
START-OF-SELECTION.
* Optional: Check if table functions can be used on this DB
**************************************************************
INSERT cl_abap_dbfeatures=>amdp_table_function
INTO TABLE gt_feature_set.
IF cl_abap_dbfeatures=>use_features( gt_feature_set )
= abap_false.
MESSAGE e030(S4D430).
ENDIF.
* Alternative with VALUE expression (Rel. 7.40)
*IF cl_abap_dbfeatures=>use_features(
* VALUE #( ( cl_abap_dbfeatures=>amdp_table_function ) )
* ) = abap_false.
* MESSAGE e030(S4D430).
*ENDIF.
* Data Retrieval
*************************************************************
SELECT
FROM s4d430_table_function( name_in = @pa_nam )
FIELDS id,
name,
city,
country
ORDER BY country, city, name
INTO TABLE @gt_customers.
* output
*************************************************************
TRY.
cl_salv_table=>factory(
IMPORTING
r_salv_table = go_salv
CHANGING
t_table = gt_customers
).
* Display
*-------------------------*
go_salv->display( ).
CATCH cx_salv_error INTO gx_excp. "
MESSAGE gx_excp TYPE 'I'.
ENDTRY.
238
© Copyright. All rights reserved.
Lesson: Understanding CDS Table Functions
LESSON SUMMARY
You should now be able to:
●
Understand the AMDP Framework
●
Define CDS Table Functions
●
Read Data From CDS Table Functions
© Copyright. All rights reserved.
239
Unit 5: Database-Specific Features of ABAP CDS
240
© Copyright. All rights reserved.
UNIT 6
Consumption of CDS Views
(Outlook)
Lesson 1
Using a CDS View as Data Source for ALV IDA
242
Lesson 2
Using CDS Views as Replacement Objects
249
Lesson 3
Generating OData Services from CDS Views
253
Lesson 4
Understanding the Consumption of CDS Views in SAP Fiori
260
Lesson 5
Understanding Analytics Based on CDS Views
264
Lesson 6
Understanding Virtual Data Models with CDS Views
269
UNIT OBJECTIVES
●
Understand ALV with Integrated Data Access (ALV IDA)
●
Display Data with ALV IDA
●
Use CDS Views as Data Source for ALV IDA
●
Understand Replacement Objects
●
Describe the benefits of SAP Gateway and OData
●
Publish Gateway Services via CDS View Annotation
●
Understand the Consumption of CDS Views in SAP Fiori
●
Understand Analytics with CDS Views
●
Understand Virtual Data Models (VDM)
© Copyright. All rights reserved.
241
Unit 6
Lesson 1
Using a CDS View as Data Source for ALV IDA
LESSON OBJECTIVES
After completing this lesson, you will be able to:
●
Understand ALV with Integrated Data Access (ALV IDA)
●
Display Data with ALV IDA
●
Use CDS Views as Data Source for ALV IDA
Reminder: Classic SAP List Viewer (ALV)
SAP
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Figure 170: SAP List View (ALV)
SAP List Viewer (ALV) is the preferred technique to display and format list-like data in SAP
GUI-based applications (reports and dialog transactions).
242
© Copyright. All rights reserved.
Lesson: Using a CDS View as Data Source for ALV IDA
I
8./Wr'iJ
t
1
I
±4±
I
I
�
� ----------------------------- :
UI Info (@A 1@1')
External Format
I
Raw Data
Authority.
Business
Check
Data
l
Relevant data is extracted in�o an internal table after the application performs the
necessary authorization checks
Calculated Business Data columns may be added by the application
UI information {for example icons or links) is added
ALV services manipulate the data (sent via an internal table) based on user interaction
Required data is displayed on the screen
Figure 171: Classical ALV – How It Works
The figure shows the approach to displaying data using the classical ALV. The steps shown
provide an example of what the ABAP application would typically do.
Classic a I ALV Problems
•
Working with huge amounts of data (potentially millions of records)
•
Initial Load -All data needs to be loaded from the database into an internal table
•
Sorting, filtering, grouping can take a substantial amount of time
Demo: Data display with Classical Al V
PA_CUR
so.cus
SO_AGCY
to
to
Users may restrict the amount of data to be shown lo try to speed up processing
Waiting too long before results displayed
Runtime errors can occur due to memory consumption
Figure 172: Classical ALV – Problems
For an end user, working with large amounts of data in a classical ALV can be cumbersome
and time-consuming. The issue is that it is optimized for the old paradigms and constraints,
where the database is considered the bottleneck. The classic ALV requires all data to be first
loaded into an internal table in order to display it. Typically, this is larger than what is actually
displayed to the user.
© Copyright. All rights reserved.
243
Unit 6: Consumption of CDS Views (Outlook)
This initial load can lead to very long waiting times for the end user, or even short dumps due
to memory consumption. Due to these issues, the user may restrict the amount of data
beforehand, leading to incomplete data sets.
Once the data is loaded, all processing takes place in the ABAP stack on the internal table, for
example, sorting the data set, filtering the data set, grouping, aggregating, or adding
calculated columns. Even paging through the result set happens in the ABAP stack. All of
these processing steps can take a long time, and again consume a large amount of memory
when dealing with large amounts of data.
Clearly, the way in which the classical ALV works contradicts the new Code-to-Data approach.
This is the reason for the new variant of the SAP List Viewer.
ALV with Integrated Data Access (IDA)
The ALV with intergrated data access (ALV IDA) is significantly different to the classical ALV –
especially when used in combination with ABAP CDS.
Table or View
-,_)_
L�<R�:· -----.--------�---_]
-- .........
UI Info (e,A1@)
....
,
-
External Format
.
.
�
Authority checks, table functions, paging, sorting, filtering are now performed by the
database via the relevant parameters
UI information is still handled by the application
Amount of data is severely restricted by the detabese before it is displayed on the
UI and it is not required to store ii in an internal table.
Figure 173: The new approach – ALV with Integrated Data Access (ALV IDA)
Authority checks, table functions, and other processes that were previously carried out by the
application are now performed by the database. The application only has to pass the details to
the new ALV API;
For example, a WHERE clause can be sent to the database by calling relevant methods.
Additional UI information is still handled by the application.
The amount of data is severely restricted by the database before it is displayed on the UI, and
there is no longer a need to store the displayed data inside an internal table.
I»
244
Note:
Package SALV_IDA_TEST contains sample programs using the ALV IDA.
© Copyright. All rights reserved.
Lesson: Using a CDS View as Data Source for ALV IDA
• Reduced toolbar compared to the classic ALV
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• Users can select a column or a cell and
make use of several options in ·the context
menus
• The layout, sort and filter settings can also be
changed using ·the Change Layout
button
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Figure 174: ALV for HANA – End User Perspective
The ALV IDA will look and feel familiar to end users who have worked with the classical ALV,
but there are some small differences in functionality and behavior.
Data Display with ALV IDA
Relevant interfaces:
if_salv_gui_ ... ida
DATA:
go_salv TYPE REF TO if_salv_gui_table ida,
go_full TYPE REF TO if_salv gui fullscreen ida.
Factory method for
ALV IDA instance
go_salv = cl_salv_gui_table_ida=>create ,(
io_gui_container
iv table name
= 'SBOOK'
=
-.
),
-
go_full = go_salv->fullscreen().
go:_full->display().
Optional: Assignment
to a container
Alternative: Create
fullscreen object
Same coding with
method: chaining
cl_salv_gui_table_ida=>create( iv_table;_name = 'SCUSTOM'
) ->full.scrseen ( ) ->display ( ) .
I
Figure 175: Example: ALV IDA in Fullscreen Mode
The coding example shows how you can display the content of a table using the ALV IDA in a
report.
© Copyright. All rights reserved.
245
Unit 6: Consumption of CDS Views (Outlook)
Instead of feeding the ALV instance with the data to be displayed, you only have to specify the
table (or Dictionary view) the data come from. The ALV will read the necessary data (and only
the necessary data) from that data source.
Regarding the display, you can either link the ALV IDA instance to a container control
(optional parameter io_gui_container) or you can create a fullscreen object (method
fullscreen).
Note:
With method chaining (available as of Release 7.02) the entire coding becomes a
single ABAP statement.
ALV IDA Based on a CDS View
Ill
t
DA.Tl\:
go salv TYPE REF TO if_salv_gui_table ida,
go_full TYPE REF TO if_salv_gui_fullscreen_ida.
Special factory
method for CDS views
go_salv
cl_salv_gui_table_ida=>create_for_cds_view(
. 0 Cf'_/ i C: , r t el � e
'S4D430 ALV IDA'
iv eds view name
-
,
I
-
)
.-
go full; go salv-�fullscreen( l.
go_full->display( l.
Name of CDS View
{not the SOL View)
Figure 176: Example: ALV IDA Based On a CDS View
The coding example shows how you can display data from a CDS View. You have to call the
dedicated factory method create_for_cds_view if you want your ALV IDA to read from a CDS
View.
Regarding the display, the same options exist as with factory method create.
246
© Copyright. All rights reserved.
Lesson: Using a CDS View as Data Source for ALV IDA
Selections and Input Parameters
SELECT-OPTIONS:
so_cus
Helper class to
FOR gs_dQtQ-customid.
aggreg1ate rang:es
DATA:
go_range_collector TYPE REF TO cl salv range_tab_collector,
gt_named_ranges TYPE if salv_service types- ·yt_named_ranges.
go_salv
cl_salv_gui_table_ida=�create_for_cds_view(
iv _cds_view_name = 'S4 u., jJ
u ' ) .
CREATE OBJECT go_range_collector.
go_range_collectox->add_xanges_for_name( iv_name
it_xanges
I
'CUSTOMID'
so_cus [] } .
go_range;_collector->get_colleoted_ranges(
IMPORTING et_na:med_ranges
gt_named_ranges).
go_salv->set_select_options{ it-ranges
gt_named_ranges).
Figure 177: Example: Data Restriction with Select-Options
The coding example shows how you can use select options (range tables) to restrict the data
your ALV IDA displays.
You do so by calling method set_select_options of your ALV IDA instance. For this method,
you have to convert the select options and combine them into one internal table.
The recommended way to do that is to use an instance of helper class
cl_salv_range_tab_collector.
PARAMETERS:
pa_cur TYPE s4d430_s_classical_alv-currency DEFAULT 'USO'.
DATA:
gt_params TYPE if_salv_gui_types_ida=�yt_parameter,
gs_param TYPE if_salv_gui_types_ida ys_parameter.
go_salv
cl_salv_gui_table_ida-'create_for eds view(
iv_cds_view_name = 'S4J4{v LV �JA'
gs_panm-name = 'CURRENCY_IN' ·
Fill internal table with
namelvalue pairs
gs_param-value = pa-cur.
APPEND gs_param TO gt.yarams.
'
go:_salv->set_view_parameters( it_parameters
name
value
J
gt_params ) .
Alt.ernativ syntax with
VALUE expression
go_salv->set_view_parameters(
it_Farameters =VALUE#( (
) .
'CURRENCY IN'
pa cur
) ) J.
Figure 178: Example: Providing Values for an Import Parameters
© Copyright. All rights reserved.
247
Unit 6: Consumption of CDS Views (Outlook)
The coding example shows how to deal with a CDS View that has input parameters. To
provide values, you have to call method set_view_parameters for your ALV IDA instance. The
method expects as input an internal table with pairs of parameter names and actual values.
As in the example above, you can fill this table with ABAP statement APPEND. Alternatively,
you can omit the helper variables gt_params and gt_param if you use a VALUE expression
(available as of Release 7.40).
LESSON SUMMARY
You should now be able to:
248
●
Understand ALV with Integrated Data Access (ALV IDA)
●
Display Data with ALV IDA
●
Use CDS Views as Data Source for ALV IDA
© Copyright. All rights reserved.
Unit 6
Lesson 2
Using CDS Views as Replacement Objects
LESSON OBJECTIVES
After completing this lesson, you will be able to:
●
Understand Replacement Objects
Replacement Object Principle
ASAP Program
SELECT
FROM •••
CDS View
Transparent
Table
Access redirected to
replacement object
CDSSQLView
Database Table
Figure 179: The Basic Idea of Replacement Objects
A CDS view can be defined as a replacement object for a database table or a classic database
view in ABAP Dictionary.
If a replacement object has been assigned, any read access via Open SQL statement SELECT
will be redirected to the replacement object.
© Copyright. All rights reserved.
249
Unit 6: Consumption of CDS Views (Outlook)
ASAP Program
INSERT
DELETE
MODIFY
CDS View
Replacement ignored
for write accesses
CDSSQLView
Transparent
Table
Standard
Behavor
Database Table
Figure 180: Replacement Only for Read Access
Replacement Objects only take effect for read accesses. Any write access to the table is not
redirected.
Prerequisites for Replacement Objects
• Matching Structure Type
- Same number ct components
- Same component names (exception: client field)
- Same technical types, including length and decimals
- Note: Order of the components can be different
• Restiriction for the CDS View
- No input parameters
• Restriction in Customer Syst.ems
- Replacement objects only for (own) Dictionary views
- No replacement objects for tables
J
250
Figure 181: Prerequisites and Restrictions
© Copyright. All rights reserved.
Lesson: Using CDS Views as Replacement Objects
Assigning a Replacement Object
�
�nment
Sr.:tem
1;!!11
T.ble L�!lQ!n .
jibhial saa (h .
!!le11rdlr Dlipliy
C'tdt511tt+IF!2
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Ai;tmtilln T:(11a ...
Oiil!lgeJD!wbY .I�� CiihlQil'l'
�hanc�ment cat@')O.f'I' .••
!"rol\YObi«I. ...
�ho-,/H,:le SWlteh
@
KQG[I )ff300 Oeflle/01.J,nge Proxy Ot;Ject
i3ble:
Proi,:yObject
fo1
S4 .
.:
S4!>130_:SFLJGHTJI
rS4D43a M:PI.Ji.cri-<.oo
"'
-
Figure 182: Assigning a Replacement Object
In order to make a CDS view the replacement object for a table or classical Dictionary view,
proceed as follows:
1. Open the table definition or Dictionary view (transaction SE11, SE80).
2. From the menu, choose Extras→
Proxy Object….
3. On the dialog box, enter the name of the CDS View.
4. Choose Apply.
[o
Hint:
In older releases, the menu path was Extras→
Replacement Object….
If you define a replacement object for the first time, the system checks whether the specified
CDS view meets the prerequisites. If a CDS view used as a replacement object is changed
later and the prerequisites are no longer met, a runtime error
DBSQL_REDIRECT_INCONSISTENCY occurs when an Open SQL read is performed on the
database table or on the database view.
© Copyright. All rights reserved.
251
Unit 6: Consumption of CDS Views (Outlook)
Application Scenarios for Replacement Objects
• Elimination of Aggregate Tables
- Replacement of aggregate tables (filled in background jobs)
- The replacing CDS Views aggregate the data in real time
Benefit:
Easy and central redirect of all read accesses
• Support for Re�design of Data Model
- New data model to substitute old data model
- Replacement of old database tables
- The replacing CDS Views access the new tables
ano reconstruct the content of the old tables
Benefit:
Easy and central redirect of all read accesses
Attention: All write accesses have to be adjusted manually!
I
Figure 183: Important Application Scenarios for Replacement Objects
LESSON SUMMARY
You should now be able to:
●
252
Understand Replacement Objects
© Copyright. All rights reserved.
Unit 6
Lesson 3
Generating OData Services from CDS Views
LESSON OBJECTIVES
After completing this lesson, you will be able to:
●
Describe the benefits of SAP Gateway and OData
●
Publish Gateway Services via CDS View Annotation
SAP Gateway Introduction
The growth of the mobile device sector is driving the demand for new innovative applications
for business and enterprise.
The large number of developers who are developing these applications very often have
knowledge of technologies such as .NET, JAVA, and HTML5, but without a strong SAP
background, they would need an interface to the SAP Business Suite systems to develop for
SAP platforms.
-D
Support:
End-to-end scenarios
New devices and
experiences
Growing new communities
of agile developers
Simple aooess to complex
enterprise systems
Expansion or business data
and decision makers
Manage and control mission
critical systems AND deploy
innovative solutions
Consumer innovations in
the enterprise
Figure 184: SAP Gateway
Mobile access to complex enterprise systems and expanding business data requires that SAP
customers can manage and control mission-critical systems, and deploy innovative solutions
at the same time.
SAP Gateway is an innovative solution for simple and robust business enterprise mobile
access.
© Copyright. All rights reserved.
253
Unit 6: Consumption of CDS Views (Outlook)
Key Challenges in Enterprise Computing for Business Consumers
I> SharePoint
O Office
Socia!
Mobae
Browser
Enti!rprls11
Enterprise
Plaifonns
Devices
Based
Software
Cloud
Point to Point Solutions
Increase Costs & Complexity
SAP Business Sutte
Figure 185: Enterprise Computing for Business Consumers Key Challenges
The problem in the past was that for different consumers a developer had to build a specific
integration scenario that used its own protocol. However, one-off applications specific to each
device or platform were not transferable. For example, a solution built for browser-based
applications could not be used for an integration of enterprise software. The solution is to use
one protocol, the OData protocol.
254
© Copyright. All rights reserved.
Lesson: Generating OData Services from CDS Views
The Solution: OData
Ill> SharePoint
O Office
Social
Plaifonns
Mobne
Browser
Based
Devices
Enterprise
Enterprise
Software
Cloud
••••--- -SAP Gateway
CRM
SRM
SCM
PLM
EIRP
SAP Business Suite
Figure 186: The Solution: OData
OData was originally invented by Microsoft and shared through the open specification
promise. It has become an industry standard; the latest version, version 4 is an OASIS
standard, which is now driven by SAP, Microsoft, IBM, and a number of other companies.
SAP Gateway is used by SAP Business Suite and SAP S/4HANA to publish OData services
built on top of the ABAP application server. SAP Gateway enables consumption of SAP
Business Suite and SAP S/4HANA data for people-centric applications across multiple
channels.
What is OData?
The most important point is that the OData service forms a kind of contract between the nonSAP side and the SAP side, helping to bring together developers on both sides.
OData Benefits
Based on Representational State Transfer (REST), OData provides compelling benefits for
SAP application development, which include the following:
●
●
●
It is relatively lightweight and builds on the HTTP protocol allowing database-like access to
data via the web.
In addition to being an industry-standard protocol for creating and consuming data APIs,
the OData protocol became an Organization for the Advancement of Structured
Information Standards (OASIS) standard with its latest version, OData v4.
OData allows for a decoupling of the data provisioning from the UI designers by providing a
contract between the non-SAP developer or UI designer and the SAP developer.
●
Because it is supported by various platforms, it supports multichannel access to SAP Data.
●
It has been broadly adopted; the main drivers are SAP, Microsoft, and IBM.
© Copyright. All rights reserved.
255
Unit 6: Consumption of CDS Views (Outlook)
●
●
The standard address representation or resource is the Uniform Resource Identifier (URI).
OData supports two formats for representing the resources it exposes; the XML-based
AtomPub format and the JSON format.
SAP Gateway Architecture
SAP Gateway 2.0 is technically based on ABAP add-ons that are deployed to the SAP
NetWeaver stack (7.0, 7.01, 7.02, and 7.31).
There are add-ons that provide the SAP Gateway Server functionality (GW_CORE and
IW_FND) and there is an add-on (IW_BEP) that provides the SAP Gateway backend
functionality. The add-on IW_BEP is deployed on the SAP Business Suite backend because
that is where the service development takes place.
With SAP NetWeaver 7.40, the software components of these add-ons are delivered as part of
the SAP Basis in a single software component, SAP_GWFND. This means that the software
components for the backend functionality, as well as the software components for the SAP
Gateway server functionality, are available on every system running on top of SAP NetWeaver
7.40.
OData
SAP Gateway
Gateway Backend Enablement
SAP HANA I Any DB
SAP Business Suite
Figure 187: SAP Gateway Architecture
256
© Copyright. All rights reserved.
Lesson: Generating OData Services from CDS Views
OData Service Development with SAP ABAP CDS Views
OData Service Development with CDS
0
fJ
e
J
Mapped Datasource - SEGW
Import DDIC structures, create associations and
map them to CDS views
Referenced Datasource - SEGW
Generate an OData Se1ivice from a CDS
including associations
OData.publish: true· ADT
Generate OData Service without SEGW
l
Figure 188: OData Service Development with CDS
There are three options to leverage CDS views in an OData service development in SAP
Gateway. The options are as follows:
●
First option
-
●
Second option (no mapping required)
-
-
●
As of SAP NetWeaver 7.40, you can map a CDS view and its associations to the entity
sets and navigation properties of an OData service.
You can redefine the methods of the MPC_EXT and DPC_EXT class to implement
enhancements on the OData model or service implementation level.
As of SAP NetWeaver 750, CDS views can be used as Referenced Datasources in
SEGW.
Third option (no mapping required)
-
You can set an appropriate annotation OData.publish: true. The generated service does
not offer any enhancements on the SAP Gateway level.
In this introductory lesson, we will focus only on the third option.
© Copyright. All rights reserved.
257
Unit 6: Consumption of CDS Views (Outlook)
Oeslgntlme,
Runtime
Bro� (Fl«I launchpad)
SAP Fioriapp
SAP Web IDie
Ul5
HTTPS
HTMl/OOata
IIWFNDIMAINT_
SERVICE
T�clRFC
SAP NecWeaver 7.52 (ABAP OData Provider)
SAP Gateway111untlmei
(backendJ
1-�&-1
SA!ll
{G�n�rl, !lPC!lMll'C]
Read
ABAP
aaehnd Bu$lnou Logfe
(ClassEs,aAl!'I, I
Developmerit
Tools
CDS
View
Figure 189: SAP Fiori Programming Model — SAP NetWeaver 7.4
With SAP NetWeaver 7.40 or later, it is possible to use SAP Gateway for building OData
services that read access to CDS objects.
Use CDS views as mapped data sources, it is no longer necessary to use coding for read
access.
Requests that perform changes require additional manual implementation.
Gateway Service via CDS View Annotation Publishing
@Ab, p(gp loE! &q IViewNall'!e; • ZSEPN_lSOf_TPL.
@MapCataloe cor,1piler c0mp�reFilteca tr-ue
�ces cootrol. <1u horha
@l;ndlJserlext.l_;,llel:
on(heck, =CHECK
·�le;sOrders - EPM Demo Data'
@Ql!>a:ta. publfs h : true
define view l�C��-l�'i9-rd�_l_
"" select fr""' Sll:'!Ll_Scal!tJ,jkol_<tr_�
{
-
���
l.l'l��l'MIII'
��·Er+1�0MI NPHC:5tfff!'fffPU'I l'Jli
.. ,�
j�.,._...,p•'"""".......,"""'"
ls.y$lelnAl>MeS
�ftN.tu�'Sl.a
�
'l,wrwd�
W':!r,wm.wli
�
�
la4�-
Figure 190: Used Code
258
© Copyright. All rights reserved.
Lesson: Generating OData Services from CDS Views
Development Flow:
1. Create CDS view with annotation: @OData.publish: true
2. Service is generated in the SAP Business Suite Backend System
(Name of generated Service: <View Name>_CDS)
3. Service can be published in the SAP Gateway Server (Frontend Servcer) (Transaction /
IWFND/MAINT_SERVICE)
Actlv.tt-e and M.tlnt-aln Services
lype _ TeclYiicil Sem::e Name
SEP ZSEPM c SALESORIER TE\ cps
I � !CF Node
• JI
. cal �
"'v .. sern:e oescr.:ioon
External Service Name
1 Sale:sO!rders • EFlf.t De1111'J Data
�SAP Gateway Client
ZSEpM
c SALESORDER
N.;imasp;
IP\-
cps
I
]CiF Nodes
System Aliases
SAP System Alas
LOCAL
Desotitbn
Local System �
Figure 191: Result
LESSON SUMMARY
You should now be able to:
●
Describe the benefits of SAP Gateway and OData
●
Publish Gateway Services via CDS View Annotation
© Copyright. All rights reserved.
259
Unit 6
Lesson 4
Understanding the Consumption of CDS Views
in SAP Fiori
LESSON OBJECTIVES
After completing this lesson, you will be able to:
●
Understand the Consumption of CDS Views in SAP Fiori
Fiori Applications Based on ABAP CDS
For standard Uls Fiori Elements
generates the UII • no coding needed
01
02
D t Model rng
Expose
OData service
Ba.ckend Developer
ABAP in Eclipse
ABAP I CDS Sources
Backend Developer
ABAP in Eclipse &
SAP Gateway Tools
Gateway Services
UI Developer
Role
WeblDE
Toolset
Ul5 Sources
Entities
Figure 192: Key steps and Development Tools
The development of SAP Fiori applications starts with the data modelling phase.
After the back-end developer has built ABAP CDS sources, he or she uses the odata.publish:
true annotation to registers the OData service in the backend. Then the developer publishes it
to the SAP Gateway Hub system using transaction /IWFND/MAINT_SERVICE.
In this lesson, you will see how the UI developer finally takes the published service to generate
a user interface. To do so, the developer uses SAP Web IDE.
Note:
Standard UI Fiori elements generate the complete UI, so that no coding is required.
260
© Copyright. All rights reserved.
Lesson: Understanding the Consumption of CDS Views in SAP Fiori
Fiori Elements
001
\/>,
omet '-APV,
I
c
�
Ol.!t!kStli'I
N n·Plot*CI
from lllrr:l)l;III
-
wtliU)'DUl
..
rrpor
�
-
�
ifil;ll
-
NNPf<llld
tO/IISO/n
_.,,
..._. ..,,
KS
�
$,l'Ul$"8AP
Cio.,.komOI
R-�
lla>o"°'l'
SAP .�IOf�p;lg(l
·,AP '.
ICE 000:..
A$ a� en SAP comml.lNl'j'
SAP Fi0<10esign
ilJeine$
SAP . ICE $OK
'Af'Vi5SOK
T lOI'
Figure 193: Landing Page in SAP WebIDE
After the user logged on to SAP WebIDE, he or she can start development by creating a new
project.
In order to use SAP Fiori Elements, the new project should be based on a template.
x
BasK:.JnEorma.tioo
New U5t Report Application
Template Selection
Sear Gil
SCi!By
SAP F!OII Ma51er-OotaU
ll!lPIIU::.on
•
Noxl
oil!
"ti
o.... rv1.... i>""""
Apr,lla1io,,
t,
Figure 194: Template List Report Application
List Report Application is one of the templates offered by Fiori Elements. It creates a Fiori
application with a list display and is based on an OData service and a CDS View.
© Copyright. All rights reserved.
261
�,
Unit 6: Consumption of CDS Views (Outlook)
�
Run �.maxnlnll
....
<f'
00
Wllll<sp;!Ce
a
S1and�r�
�
G
City
Counuy
c5l
Q.
se.,rc11
�
Fllgl!t BOOltings (100.110)
..,_
COMe
Standard·
Fll,ilU03".c
0
Parme
Bco1<111gn-.
(uStomll<natne
00000001
11900 USD
USO
jl(U
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�:i.·11
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onnsiopn R�a•
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USO
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Ol!tis ne o·o.,u-.
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USO
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161 30 USO
USD
M,34!,,!l�.01 US'O
USO
AA
-
•
Figure 195: Testing the Application
The generated application is tested in SAP WebIDE by running the project in flpSandbox.
UI-Specific Annotations
@Abap(atalog .. sqlViewName: 'S4D430_0DFIORI'
Set a Caption
for the List Display
@OData.publish: true
@UI.headerinfo: { typeName:
'Fl'ght Booking',
typeNamePlural: 'Flight Bookings'}
Enable a
Search Dialog
@Search.searchable: true
define view S4d430 OData Andl_Fiori as select
from sboolk
association[l] t,o scus tom as _customer
Display this Column
and Set the Position
on customid ; ; _;customer, id
{
@UI.lineitem: { position: 10, importance: #HIGH}
@UI. selectionField. position: 30
key carl"id,
l
Display this field in
the selection dialog
1
}
Figure 196: UI-Specific Annotations
UI-specific annotations in the CDS View influence the way the UI is generated.
Here are a few examples:
262
●
Annotation @UI.headerInfo: specifies a Caption for the list display.
●
Annotation @Search.searchable: true enables a search dialog.
© Copyright. All rights reserved.
Lesson: Understanding the Consumption of CDS Views in SAP Fiori
●
●
Annotation @UI.lineItem: makes this field a column in the list display. The number after
addition position sets the position of the column.
Annotation @UI.selectionField: adds a corresponding UI element to the selection dialog.
Selection via airline
{3rd selection field}
Search Function
Switched on
Standerd
G
c,iy
OounDy
Ain,ne
Sea't'll
MapiF,ltff:S
Flight Bookings (100,110)
Sland�rd'
F1win10;,ie
a
Header
9
Payrne
Al�.r)e
Coone
Bool\lng aumber
CU$tolner""me
AA
0017
212-JJH
00000001
JCIMnn Butliltr
719.00 USD
U&O
AA
0017
212'Si'17
00000002
Cllm«lpn Ryan
761 JO USO
USO
M
0017
2.r23J17
00000003
Cllns ne O"Oul�
76130 USD
USO
AA
0017
�17
ll0000004
Anna Oumb;!Cih
761 30 USO
USO
u.u · �39.ot u so
use
i:«e
•
Column Airline is
visible in the list display
Figure 197: UI-Specific Annotations – The Outcome
The figure illustrates the outcome of these UI-specific annotations.
LESSON SUMMARY
You should now be able to:
●
Understand the Consumption of CDS Views in SAP Fiori
© Copyright. All rights reserved.
263
Unit 6
Lesson 5
Understanding Analytics Based on CDS Views
LESSON OBJECTIVES
After completing this lesson, you will be able to:
●
Understand Analytics with CDS Views
The Query Browser
A Design Studio app as Fiori content
No installation
Ad-Hoc Reporting
Figure 198: Query Browser Overview
The Query Browser is a default Design Studio that is available in the standard Fiori content.
No additional installation is required as this application is shipped with the standard Fiori
content.
The Query Browser allows the end user ad-hoc reporting based on CDS Query views.
264
© Copyright. All rights reserved.
Lesson: Understanding Analytics Based on CDS Views
Figure 199: Launch Query Browser from Fiori Launchpad
The Query Browser is a Fiori application. To be able to start it, you first need to start the Fiori
Launchpad. The Fiori Launchpad can be started using a browser.
.
'
a.
V,ew Detal �v
ZOO_ANALYTICS_QUERY
Name of the CDS View
OOmoMa�'\JCS-�
�1,:w,Cor1lfl(>fle,,1
�
Display the Annotations
from rhe CDS View
Dt><J1>1J011
Anl!o<oli>n
i)tli'I"""'
CQl,Jmn�me
031> ... .....,[
COIUmnOt�
C<>kimn Do� Trpo
CARRIO
S_CAAA_10
AiNnt�
C>!AA
co
s_com,1_10
ng•i�""""'�'
........ c
fLOI\TE
S_OAT!::
flGli!GOI!
DAIS
900><JD
S_BOOK_ID
Boo'*1goomboer
Nl.ll�C
CUSlO,,I D
s_cUSTOMEFI
customer Number
NUMC
IW,IE
S_CIJSTH.•,ME
Cu��rl'\ilme
CWIR
ClrY
CITY
Cc
CHAA
C-()UNTF;iV
S_OOUmRY
C<Hmlt\' Code
O!AA
Cl.ASS
S_Cl.l\SS
flglltClas.
CHAA
s_c�
�)'f!l<flCamenq
ID
PRlct:
CURR
eounn u:ngm
l5
�
15
CUFIFI
OAl'S_AHEAD
CUl(Y
,,ir,
,o
*
M<I laQ< fDC1' II
�n SIIJl!II)
Figure 200: View Details and Launch Query with Design Studio
The View Details are displayed. The header shows the name, application component, tags,
and the description.
The Definition tab shows the technical details like Column Name, Data Element, Description,
Data Type, and Length of all columns.
On the Annotation tab, you will see additional details on access control, VDM view type,
Analytical query, End user label, and the ABAP catalog view name. The CDS in-front of the
ABAP catalog view name means it is a CDS view.
To open this query in the Design Studio, click Open in Design Studio.
© Copyright. All rights reserved.
265
Unit 6: Consumption of CDS Views (Outlook)
Q
Demo: Analytics - Info Sourcev
Standard
0
snow !'11ter ear
«
0..
F
COLUMNS
DIMENSIONS
er,
.1,lll:im
Measure�
Im
O
...
• AZ
� �tCE
., AlrHne
soo1u1111numtJef
Cily
Class
C,,,noe�n Numbe1
a.stomf-t
i.;l'nlii4!r
ROWS
Custorne-rna.me
Alrl,ne
-�1
.Al�•n• •
FIFtlCE ,•
AA
;.>7'"1.13
S 159.872 6-14 a.3
FllgMD3te
AZ.
PaymemcYrrency
OL
S67!>73'131,12
JL
1..H
S 2'l9 $&<; 55S.!i-2'
S 57.325076.dl
OF
S !2.7M 579,M
so
S 3W.l95.206,65
VA
S l$46'1iff1,d0
export lo Excel
li:ilS&MEIMd
Figure 201: Ad-hoc Analysis Design Studio Template
The resulting screen shows the selected data in a table and pie chart. The look and feel of this
result page can be customized. The query can also be saved as a Fiori tile by clicking the
Actions button on the bottom right and then select Save as Tile. In the Save as Tile pop-up,
you can specify the Title and Subtitle to be displayed in the Fiori Launchpad.
'
My ome
Home
Analysis Path Framework
odeling
KPI Design
Query Design
Revenwe By Airline
Figure 202: Result - A New Tile in the Launch Pad
The Design Studio Tile is saved under the My Homegroup for easy access.
266
© Copyright. All rights reserved.
Lesson: Understanding Analytics Based on CDS Views
Analytics-related Annotations
@AbapCatalog .. sqlViewNlame:
'54D430_ANIAQUERY'
Prerequisite for
Query Browser
true
l@Analytic:s.query;
@VDM.viewType: #CONSUMPTION
@OData.publish: true
define view S4D430_.Analytics_Query as select
from S4D430_An.alytics_Source
{
@AnalyticsDetails. query. axrs : #ROWS
key carridJ
key c;:onnidJ
Preselect this field
as ROW
Filter on this field
allows a range
@Consumption. filter: { selection Type:
#RANGE)
multipleSelections; false,
mandatory:
false }
key fldateJ
Preselect this field
as COLUMN
(Measure)
@AnalyticsDetails.query.ax.is: #COLUMNS
pr i ce,
currency
Figure 203: Analytics-Specific Annotations
Analytics-specific annotations in the CDS View influence the way the Ad-hoc is generated.
Here are a few examples:
●
Annotation @Analytics.query: true defines this view as a query
●
Annotation @AnalyticsDetails.query.axis: preselects a field as row or column
●
Annotation @Consumption.filter: allows/restricts filter settings on this field
Annotation @Analytics .. query: true
Annotation @VDM.viewType: #CONSUMPTION
• Annotation @OData.publish: true
The CDS View reads from a CDS View with Annotation
@Analytics.dataCategory with value #FACT or #CUBE
• J Figure 204: Prerequisites for CDS Views in Query Designer
CDS Views need to fulfill some basic requirements in order to be available in the Query
Browser.
© Copyright. All rights reserved.
267
Unit 6: Consumption of CDS Views (Outlook)
LESSON SUMMARY
You should now be able to:
●
268
Understand Analytics with CDS Views
© Copyright. All rights reserved.
Unit 6
Lesson 6
Understanding Virtual Data Models with CDS
Views
LESSON OBJECTIVES
After completing this lesson, you will be able to:
●
Understand Virtual Data Models (VDM)
Data Modeling with CDS Views
r-------------------------------------------------------�
i
Uls
-
iiiiH·A
!
L------------------------------------------------------�
Transactional system, e.g. SAP S/4 HANA---------�
I
/------------------------------------------------------,
+w
1
I
!
Virtual Data Model
I
F•M
:
\
I
!
MW@&
I
lr-------------------------------------------------------,
+IA +Bil F&ii
,, J
'-
I
:
I
Database Layer, e.g. SAP HANA
:
L------------------------------------------------------�
Figure 205: Virtual Data Models
SAP's focus is to create a Virtual Data Model (VDM) using Core Data Services (CDS views) to
support (and replace all other standard ABAP-related standard) operational reporting in the
context of SAP S/4HANA.
SAP's Virtual Data Model has the following use cases:
●
●
Any analytical content (e.g., queries, cubes exposed via generic analytical tools like
Lumira, Design Studio)
New transactional or analytical FIORI applications (following the SAP S/4HANA target
architecture)
●
Smart Business KPIs
●
Fact sheets and object pages
© Copyright. All rights reserved.
269
Unit 6: Consumption of CDS Views (Outlook)
•
Consumption views
Sear en
Data relii!W3l
for transaclional
appllealions
Appllealionqiecllic
\llewi;
(B<OOSS�
Vi:ews from various consumption domains
(e.g. Anallytics, Search or ... } which
consume interface views and create
queni:es on top to consume interface vi·ews
'il'leiOCt.s
obl,!J111°"'1
!Interface views
Composite views
Basic views
Database tables
E�ose �he public and stable VDM
interface for consumers.
Provide business semantics as a easii1ly
consumable and reusable data model.
Doman-specllic views {e.g. Ar1alyt11cs,
Search or ... )
Instance Authorizations via DCls
Executed via ABAP SQl Interface
Suite database model .as it i1s"
Figure 206: The Layers in the Virtual Data Model (VDM)
The key principle of the Virtual Data Model (VDM) is to build a semantic layer on top of the
existing Suite database model hiding its technical details. The above figure shows a high-level
view of the VDM.
Technically, all views in the VDM are defined as ABAP Core Data Services (CDS) views. The
most important component in the VDM is the Interface view layer. It consists of a consistent
model of reusable entity views which focus on business semantics. Interface views are
subdivided into two view types: Basic interface views and the Composite interface views.
In the top layer, the Consumption views are defined. Consumption views are created on top of
Interface views, and they address specific application requirements. Different consumption
domains (for example Analytics, Search, OData and Fiori) use interface views to consume
data, or create queries to consume the data exposed by the Interface views.
An important consequence of the above layered architecture of the VDM view model is that
consumer views must not by-pass the Interface layer of the VDM by accessing database
tables directly. For example, reports based on analytical queries (which are modeled as CDS
consumption views) will select data from interface views (for instance, from composite views
with the analytical data category #CUBE) and not from data base tables.
270
© Copyright. All rights reserved.
Lesson: Understanding Virtual Data Models with CDS Views
Consumpt on
YililWi
lnlerface views
Composite views are built selecting from the
Co�osffe vl&ws
@VDM.'lliewType set to#COMPOSITE
@Atial)itics.DataCategory 'ioith velue #CUBE,
basic views and: exploring the associations
between basic views. They can be specific to a
consumption domain or reusable in many.
#DIME:NSIONS, #FACT, #TEXT or
#HIERARCHY
@VDM-busine�Objoct (to be decided)
Basic Vl&ws
IC are Entitles I Te Kt Views I Hierarchy Viewsl
Dirtingu.,hed b�
@VDM.viewT'l'J)e set to #BASIC
@Anel:,tics.DataC�tegory with value
#CU81,. #DIMENSIONS. #FACT. #Tl,XT or
Basic views form the low-redundancy model on
top of the Suite database tables. Core entity
views contain the associations to other core
entity views.
#HIERARCHY
@VDM.b4.Jslr!e'osObJect (to be de(lde-d)
\
(
}
Database tables
)
Figure 207: Interface Views Divided into Basic and Composite Views
Basic Views are further categorized into Core Entity views, Text views, and Hierarchy views.
Core Entity Views
Carry the business semantics, along with all data that semantically belongs to the Core
Entity. Independent from clients, Core Entity views contain the keys that represent the
core entity. Core Entity views also contain the associations to all other business objects
('external relationships') and to the other directly related BO nodes if existing ('internal
BO structure'). The Core Entity views are often used for Master data like
SalesOrderHeader, SalesOrderItem, CostCenter, ControllingArea.
Text Views
Contain language-dependent texts for a specific business entity.
Hierarchy Views
Contain hierarchy nodes (incl. parent/child assignments) for a specific business entity.
© Copyright. All rights reserved.
271
Unit 6: Consumption of CDS Views (Outlook)
Data Model-Related Annotations
@VD'M. view Type
• Admissible Values: #BASIC. #COMPOS/TE, #CONSUMPTION. #EXTENSION
• In VDM, all
cos views
shall be annotated ex-plicilly with a VDM view type
• @VDM.prlvate
• Admissible Values: #blank (=true), true or false
• Only private vievvs need to be annotated explicitly
• @ObjectModel.dataCategory
• Admissible Values: #TEXT, #HIERARCHY
• @Analytlcs.dataCategory
• Admissible Values: #FACT, #CUBE, #DIMENSION
]
Figure 208: Data Model-Related Annotations
Dedicated annotations allow to document the layering of the VDM right in the DDL sources.
They also support the classification of CDS views as “private” with the consequence that they
will not be visible for certain consumers.
LESSON SUMMARY
You should now be able to:
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272
Understand Virtual Data Models (VDM)
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