Project synopsis
Database scheme driven GUI construction for the Internet or a desktop application
By
V S Narayana Raju Datla
(Roll No:-06CS6024)
Under the Supervision of
Prof. Chitta Ranjan Mandal
Department of Computer Science & Engineering
Indian Institute of Technology, Kharagpur
Approved by
___________________________
__________________
Signature of Project Supervisor
Signature of Student
Abstract:
The graphical user interface (GUI) generation for many software manually is
tedious task and time consuming job. This work tries to addresses these two drawbacks by
generating the GUI automatically. This was met with limited success because of the added
load on the human designer. In this work we have used a methodology along with user
specified stored procedures to create an interface forms that are used by the user to interact
with backend database system.
This tool does not require specifying a single line of code for user interface (UI)
except input for the tool and Stored Procedure. It will generate and displays the forms that
are available to the user. Apart from these forms this tool it self generates the basic queries
like INSERT, DELETE, UPDATE, CREATE that are executed on the base tables.
We have used JAVA to develop this tool and we have tested our results by using
SQL SERVER. We have developed this tool on LINUX platform.
1. Introduction:
Problem statement:
User interface will perform a crucial role in the success of the software. Until now
most of the user interfaces are developed manually and this development will consume lot
of time and cost. To overcome these draw backs we are trying to develop a tool that will
generate the user interfaces automatically for all types of applications. But, this automation
has met with limited success for application such as database driven systems.
In this work we aim to develop a tool for the construction of user interface forms for
internet or desktop applications automatically from database schema. We have developed
the methodology that has described below. But user interface forms from schema are may
not sufficient for all applications, therefore we are using the feature (Stored Procedures) of
Structured Query Language (SQL) to get the needs of the application. The methodology
will create basic interface forms directly from database schema and the stored procedures
will generate the forms as per the requirement of the user.
Back Ground:
In 1980’s, the user interface systems specified as a state transition diagram or event
based representations to specify the interface in response to events. With the improvements
in these representations, now-a-days the model-based tools are raging from automatic
interface generators to tools that offer advice to the designers. Initially the automatic
interface generator uses the data models as input to the tool. But these tools have some
problem if the user may need data from different multiple tables on the same interface.
So the data model is not enough to get the required forms. Therefore we have used user
specified Stored procedures in this tool.
The form construction is proceeding in two steps.
In the first step the system will take the schema as input which consists of entities,
relationships and attributes. The tool creates the relational tables in the backend database
on the input specified and generates the forms by using the methodology. The navigational
units present in the form are those entities that are related to the form (i.e. either entity or
relationship).
In the second step the user has to specify the queries in ‘stored procedures’. Because
the user interface is application dependent, all the interfaces are not possible from schema.
Based on those procedures specified by the user we will get the required forms.
This tool can be used for both internet and desktop applications. We will describe
the methodology for the first step i.e. generation of the forms from database schema.
2. INPUT:
Input to the procedure going for any graphical input, just we will do it like a text based
input. Basically the input to the tool is Extended Entity Relationship (EER) schema
because the tables itself not take care of all the relations in EER schema. The input was
entered as a text. So i made some representations for the schema. The string that I enter is
a relationship between entries.
The entries in the database:
The input to the tool is categorized into the following six ways.
1. Entity sets
2. Relationship sets with 0/1 cardinality on at least one side, and any cardinality on the
other,
3. Relationship sets with m: n cardinality and n-ary relationships
4. Multi-valued attributes
5. Entity subclasses that have extra attributes and/or extra relationships, with no multiple
inheritance
6. Weak entity sets (existence dependencies) with a unique identifier
2. Methodology for construction of FORMS from schema:
2.1. ENTITIES:
Relational mapping:
For this type entries create a table for the entity set. The columns of the table are the
attributes of the strong entity set. The primary key of the table is the primary key of the
entity set.
UI Mapping:
Presentation units:
For each entity set create a separate screen with all the attributes. Add update,
insert and delete buttons that allow basic database operations.
Navigation units:
The screen gets links to the screens that correspond to every m:n relationship set in
which the entity set participates, and to the screens that correspond to every multi-valued
attribute of the entity set
2.2. Relationship sets with 0/1 cardinality on at least one side, and any cardinality on
the other
Relational mapping: Add a column(s) in the table that corresponds to the entity set that
is on the “Any Cardinality” side. The column(s) we add here is the primary key of the
entity set that is on the 0/1 side and any other attributes of the relationship set.
UI Mapping:
Presentation units:
For this types of relationships use the screen that is developed for the entity set that
corresponds to the “Any Cardinality” side.
Navigation units:
For this type of relationship no additional navigation units are required.
2.3. Relationship sets with m:n cardinality and n-ary relationships
Relational mapping:
For this type of relationship create a separate table for the relationship set. The
columns of the table are the attributes of the relationship set (if any) including primary
keys of all the entity sets that participate in the relationship set. The primary key of the
table is union of primary keys of all the entity sets that participate in the relationship set.
UI Mapping:
For this relationship create a separate screen with all the attributes of the relationship
set, as well as the primary keys of all participant entity sets. Add update, insert and delete
buttons that allow basic database operations. If the relationship has no attributes then
disable the update button.
Navigation units:
The screen gets links to the screens that correspond to every participant entity set
2.4. Multi-valued attributes
Relational mapping:
For this type of attributes create a separate table for the multi-valued attribute. The
columns of the table are the primary key of the entity set to which the attribute belongs and
a separate column for values of the attribute. The primary key of the table is all the
columns of the table.
UI Mapping:
Presentation units:
For these attributes create a separate screen with the primary key of the entity
set and the multi-valued attribute. Add update, insert and delete buttons that allow basic
database operations.
Navigation units:
The screen gets a link to the screen for the entity set that owns the multivalued attribute.
2.5. Entity subclasses that have extra attributes and/or extra relationships
Relational mapping:
For these types of entities create a separate table for the super class first, using the
rules for mapping entity sets we have seen earlier. For each subclass entity set, create a
separate table. The columns of each table are the additional attributes of the corresponding
subclass entity set including primary key of the super class entity set. The primary key of
the subclass table is the primary key of the super class table.
UI Mapping:
Presentation units:
For these types of entities create a separate screen with all the extra attributes of the
subclass, as well as the primary key of the super class entity set. Add update, insert and
delete buttons that allow basic database operations.
Navigation units:
The screen gets a link to the screen that corresponds to the super class entity
set
2.6. Weak entity sets (existence dependencies) with a unique identifier
Relational mapping:
For these types of entity sets create a separate table for the weak entity set. The
columns of the table are the attributes of the weak entity set including primary key of the
corresponding strong entity set. The primary key of the table is the primary key of the
corresponding strong entity set including the unique identifier of the weak entity set.
UI Mapping:
Presentation units:
For these entity sets create a separate screen with all the attributes of the weak
entity set, as well as the primary key of the strong entity set. Add update, insert and delete
buttons that allow basic database operations.
Navigation units:
The screen gets a link to the screen that corresponds to the strong entity set
3.FORMS FROM STORED PROCEDURE DEFINITION:
It is impossible to get all the forms from the database specification. So we will take
stored procedure definition as input and produce the form corresponding to that definition.
The attributes that are there in the select clause are the attributes to be displayed as the
result of the query and those fields that are there in definition before to the AS clause and
the variables that start with the ’@’ without having the output at the end of the variable
are the inputs.
Advantages of Stored procedure:
1. Precompiled execution:
SQL Server compiles each stored procedure once and then reutilizes the
execution plan. This results in tremendous performance boosts when stored procedures
are called repeatedly.
2. Reduced network traffic:
If network bandwidth is a concern in the environment, you'll be happy to
learn that stored procedures can reduce long SQL queries to a single line that is
transmitted over the wire.
3. Efficient reuse of code and programming abstraction:
Stored procedures can be used by multiple users and client programs. If
you utilize them in a planned manner, you'll find the development cycle takes less time.
4. security :
You can grant users permission to execute a stored procedure
independently of underlying table permissions
Results:
These forms are just for taking the schema as input.
Input:
EmpId
EmpName
EmpEmail*
1
EMPLOYEES
n
n
Emp
WorkOn
Proj
dateBegan,
dateEnded
Emp
Manage
Emp
m
ProjID
ProjDescription PROJECTS
*multivalued
The output for above input is i.e. the forms generated by the tool
5. CONCLUSION:
We have implemented the methodology that will describe the forms from schema and
stored procedures concept to get the needs of the application. Here in this implementation,
we have assumed that NUMBER OF ENTITIES, MAXIMUM NUBER OF
ATTRIBBUTES, is constant through out that execution. In this we have used the SQL
SERVER as DBMS for testing our results.
References:
1. Akhilesh Bajaj , Inferring the User Interface From An EER Data Schema,
(2006), Americas Conference on Information Systems
2. Amy K. Karlson, Ralph D. Semmel and David P. Silberberg, Knowledge-Based
Information Access,
3. Korth, H., Silberschatz, A. and Sudarshan S., Database Systems Concepts, (2005),
McGraw Hill, New York.
4. Magesh Jayapandian and H. V. Jagadish,Automating the Design and Construction of
Query Forms, University of Michigan, (2006), IEEE computer society
5. NicolaAloia, Cesare Concordia and Maria Teresa Paratore, AUTOMATIC GUI
GENERATION FOR WEB BASED INFORMATION SYSTEMS, (2003)
6. http://databases.about.com/od/sqlserver/a/storedprocedure.htm
7. http://msdn2.microsoft.com/en-us/library/aa214299 (SQL.80).aspx
8. SQL Server 2000 Stored Procedure and XML Programming, Dejan sunderic, Second
Edition, McGraw Hill
9. Miguel Calejo, Mário Araújo, Sónia Mota Araújo and Nuno Soares, Web Application
Maker a model-based approach to web database development, (2002),