Guide to Migrating from Microsoft Access to
SQL Server 2005
SQL Server Technical Article
Writers: Yuri Rusakov, Alexey Kovaliov, Eduard Kolosov
Technical Reviewer: Darmadi Komo, Irena Balin
Published: December 2007
Applies To: SQL Server 2005
Summary: This white paper covers migrating Microsoft Access databases to SQL
Server 2005 and discusses the differences between the two platforms. SQL Server
Migration Assistant for Access (SSMA Access) is the best tool for this type of migration;
this paper tells you how to use it to mitigate potential problems in database conversion.
Copyright
The information contained in this document represents the current view of Microsoft Corporation on the issues discussed
as of the date of publication. Because Microsoft must respond to changing market conditions, it should not be interpreted
to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information presented
after the date of publication.
This White Paper is for informational purposes only. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR
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 2007 Microsoft Corporation. All rights reserved.
Microsoft, SQL Server, Visual Basic, Visual C#, Visual Studio, and Windows are either registered trademarks or
trademarks of Microsoft Corporation in the United States and/or other countries.
The names of actual companies and products mentioned herein may be the trademarks of their respective owners.
Guide to Migrating from Microsoft Access to SQL Server 2005
Table of Contents
Introduction ......................................................................................................1
Overview of Access to SQL Server 2005 Migration ............................................1
Microsoft Access Limitations ............................................................................. 2
Reasons for Migrating Access Databases to SQL Server 2005 ................................ 2
Migration Scenarios ......................................................................................... 3
Creating a Two-Tier Application.................................................................... 3
Creating a Client/Server Application ............................................................. 3
Rewriting the Access Application .................................................................. 4
Access Version Compatibility ............................................................................ 5
Migration Wizard ...............................................................................................5
Migrating Database Objects ............................................................................11
Schema Mapping ........................................................................................... 11
Type Mapping ............................................................................................... 13
Converting Schema Properties ........................................................................ 15
Default ................................................................................................... 15
Nullability ................................................................................................ 15
Allow Zero Length .................................................................................... 15
Converting Constraints .................................................................................. 15
Check Constraints .................................................................................... 16
Primary Keys ........................................................................................... 16
Foreign Keys ........................................................................................... 16
Migrating Indexes ......................................................................................... 16
Converting Expressions .................................................................................. 16
Handling Timestamps ............................................................................... 19
Naming ................................................................................................... 19
Table Migration Potential Problems.................................................................19
Access Table Does Not Have Unique Index or Primary Key ................................. 19
Access Table Unique Index Contains Multiple Null Values .................................... 20
Primary Key Includes Columns That Allow Null Values ........................................ 20
Access Table Contains Dates Out of SQL Server Range ...................................... 21
Access Table Contains Boolean Fields With Null Values ....................................... 21
Access Objects Have the Same Names as SQL Server Keywords ........................ 21
Access Objects Names Include Special Characters ............................................. 22
Hyperlink Column Jump Functionality Is Lost After Upsizing ................................ 22
Memo Column Is Indexed in Access ................................................................. 22
Jet Syntax Potential Problems.........................................................................23
SELECT Statement ........................................................................................ 23
Distinctrow Keyword ................................................................................. 23
-3-
Select Into Another Database .................................................................... 23
Incompatible Use of Alias .......................................................................... 24
Logical Expressions in a Select Statement ................................................... 24
TOP N Clause ........................................................................................... 24
Multiple Dot Syntax .................................................................................. 25
Common Syntax Constructs ........................................................................... 25
Expressions ............................................................................................. 25
'&' as Concatenation Operator .................................................................... 25
'\' Operator (Integer Division) .................................................................... 25
'Mod' Operator (Modulus Division) .............................................................. 26
'^' Operator (Raise to Power) .................................................................... 26
'Eqv' and 'Imp' ......................................................................................... 26
Date Literals Declaration ........................................................................... 27
Like Operator .......................................................................................... 27
Join to View Converting Issues ........................................................................ 28
Transform…Pivot Statement ........................................................................... 28
Functions ........................................................................................................30
String Functions ............................................................................................ 30
Advanced Functions ....................................................................................... 36
Domain Aggregate Functions .......................................................................... 38
Numeric/Mathematical Functions ..................................................................... 39
Date Functions .............................................................................................. 42
Data Type Conversion Functions ..................................................................... 48
Aggregate Functions ...................................................................................... 48
Data Migration ................................................................................................51
Data Transfer Source ..................................................................................... 51
Data Transformation ...................................................................................... 51
Technology Used for the Data Migration ........................................................... 51
Transaction Boundaries .................................................................................. 51
Conclusion.......................................................................................................52
Guide to Migrating from Microsoft Access to SQL Server 2005
1
Introduction
If you are considering migrating from Microsoft® Access to Microsoft SQL
Server® 2005, take into account the differences between the two platforms. This
white paper lists the known migration issues and describes using Microsoft
SQL Server Migration Assistant for Access (SSMA Access) as the tool for migration.
This white paper has the following sections:

Overview of Access to SQL Server 2005 Migration. Outlines the reasons
why a Microsoft Access user would want to migrate to SQL Server 2005, as well
as the ways to approach this task. SSMA Access is useful in scenarios in which
the Access front end will not change, but the back-end data will be moved to
overcome Access limitations and to ensure better robustness and security. The
section also contains suggestions for other migration scenarios.

The Migration Wizard. Describes how to use the SSMA Access Migration
Wizard—the easiest way to perform a migration.

Migrating Database Objects. Examines how to convert objects of the Jet
database engine to SQL Server 2005. (Jet is the Access database engine.) An
SSMA Access user can control the way Access data types are mapped to SQL
Server 2005 and how constraints, indexes, and foreign keys are transferred. As
SQL expression syntax is different in SQL Server 2005 and Access, the
replacements SSMA Access makes during the migration are described.

Table Migration Issues. Explains solutions for various problems that can arise
when converting Jet tables. For example, the linked table in Access must have a
unique column; if it is missing, SSMA Access can create the required column
automatically. Or, some Access columns might have names that are reserved in
SQL Server 2005, which can create problems after the migration. SSMA Access
provides a warning so that you know which columns are candidates for
renaming.

Jet Syntax Issues. Describes differences between the syntax of SELECT queries
in Access and in SQL Server 2005. In most cases, SSMA Access can handle the
differences automatically. For example, Access uses & as a string concatenation
operator, while SQL Server 2005 uses +. SSMA Access makes all necessary
replacements when converting the query. In those rare cases when you should
make manual updates, this section explains how.

Functions. Describes the functions implemented in the Jet database engine, and
how they correspond to SQL Server 2005 functions.

Data Migration. Offers an overview of the SSMA Access data migration process.
Overview of Access to SQL Server 2005
Migration
Microsoft Access is a database intended for small projects with few users. It is a
good tool for developing business applications, because it is inexpensive and easy to
use. Still, you may encounter problems when Access limitations prevent you from
scaling the application when your database grows large and more users need to
work with it. At that stage, you can choose the more robust and secure database
solutions of SQL Server 2005.
While the Access Jet database engine is continually updated with many quality
functional and performance improvements, it is still a file-based, desktop-class data
store. The Jet engine is not intended or architected to support more demanding
business application requirements. (For a detailed comparison of Access and SQL
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Server 2005, see Microsoft Access or SQL Server 2005: What's Right in Your
Organization?)
Microsoft Access Limitations
Access has several inherent technical limitations. Problems (slow performance,
corrupt database, application crashes) may occur if an Access application goes into
the Caution or Stop zones for any one of the reasons listed in the following table.
Okay
Caution
Stop
LAN users
<5
5–10
> 10
Internet users
0
1
>1
Frequency of use
1 x day
2 x day
> 2 x day
User permissions
Read only
Read/write
Read/write
Database size
< 100 MB
100–300 MB
> 300 MB
Data structures
Simple
Moderate
Complex
Database schema design
Good design
Poor design
Ad hoc
Reasons for Migrating Access Databases to
SQL Server 2005
Following are the main reasons for moving peripheral Access databases to a SQL
Server 2005 environment:

Allow multiuser access to a database. Access databases is popular among
users, but can handle only a few users at a suitable performance level. When
more users use the application, the Access database does not scale well. SQL
Server 2005, in contrast, can handle thousands of users, making it ideal for
multiuser environments.

Redesign and rewrite to fewer and better applications. People outside your
organization's professional IT department may have developed your Access
applications. They may not have developed the code and database according to
development standards, and they may have lacked sufficient knowledge or time.
In these situations, the entire organization can benefit from standardizing and
unifying applications and data by centralizing common processes.

Interchange data with the external world. SQL Server 2005 offers better
tools to communicate with other environments such as Oracle, IBM DB2, and
SAP. Through the Data Transformation Services/Integration Services (DTS/SSIS)
packages, you can automate data interchange with those environments or
integrate them into existing applications.

Better analyze and solve performance problems. Compared to Access, SQL
Server 2005 gives you stronger tools, such as SQL Profiler, execution plans in
Query Analyzer, the Index Tuning Wizard, and filegroups to spread data across
disks. SQL Server 2005 also has a better locking mechanism built specifically for
a multiuser environment.

Benefit from SQL Server 2005 database security improvements. There are
many benefits to using both SQL Server and Windows authentication to manage
users and access to multiple databases, database roles, and for the many ways
to grant permissions to the data they provide.
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Migration Scenarios
Migrating an Access database to SQL Server 2005 moves some or all data and data
definitions to the server. After the data is safely transferred to SQL Server 2005, you
must decide how to interact with the server-based data. The options discussed in
this section suggest possible solutions.
Creating a Two-Tier Application
You can link server-based tables to local tables in Access and use the other existing
database objects (queries, forms, reports, modules, and macros) as before. This
creates a two-tier application, in which the server running SQL Server 2005 stores
data, and copies of the interface are stored in Access on the users' computers.
Queries run on the client tier. Locally stored forms, reports, modules, and macros
provide the remaining elements of the user interface. The design of server-based
tables cannot be modified from within Access.
The advantage of this approach
The main advantage of this approach is its low transition cost because front-end
database objects do not require modifications. Users continue to interact with a
familiar interface, while SQL Server 2005 provides centralized data storage, back up
and recovery, a multiuser environment, an integrated security model, and other
advantages. After the data is in SQL Server 2005, you can begin rewriting portions
of the application by using a more robust environment such as Microsoft Visual
Studio® .NET and SQL Server 2005 Reporting Services. Moving an Access
application towards a more scalable and robust platform is referred to as upsizing.
When the migration is complete, all data is stored on the database server, and
Access continues to operate smoothly as the desktop application.
The disadvantages of this approach
The disadvantages are that queries are still processed locally, and a large amount of
network traffic is generated.
Implementation
You can implement this configuration by using either the Access Upsizing Wizard or
SSMA Access, but SSMA Access has more advanced functionality, including:

Multiple database upsizing

Schema and type mapping

A Find Database wizard

Query conversion

User-friendly interface

Improved data migration mechanism

Advanced reporting

More bug fixes
Creating a Client/Server Application
Microsoft Access introduced Microsoft Access Data Project, a new type of Access file
(.adp) designed as a client/server application. Communication between the client
and the server takes place through an OLE DB component architecture, which was
specifically designed for efficient client/server communication. All tables and data
definition objects such as views, stored procedures, and database diagrams are
stored on the server. The client stores only code-based or HTML-based objects such
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Guide to Migrating from Microsoft Access to SQL Server 2005
4
as forms, reports, modules, and macros. Most data processing takes place on the
server, and only filtered data is sent to the client, thus minimizing network traffic.
The advantage of this approach
It results in an Access application that provides the best performance and scalability,
as well as the other positive attributes of SQL Server 2005.
The disadvantage of this approach
It requires more development effort because Access objects such as forms, reports,
queries, and code must be redesigned to work directly with SQL Server 2005. In
addition, the Data Project feature may be removed in later Microsoft Access
versions.
Implementation
This configuration is supported only by the Upsizing Wizard that is supplied as a part
of Microsoft Access.
Rewriting the Access Application
In a small percentage of Access upsizing projects, the only possible is to migrate
from Access. Perhaps your existing Access application has outgrown Access, and the
program cannot meet your organization's scalability, reliability, and performance
requirements. Or, you want to migrate all or part of the application to the World
Wide Web.
In this scenario, you use your Access application as the start of a new design. You
use additional technologies such as Visual Basic® (VB), Active Server Pages (ASP),
and Visual Studio .NET to rewrite the Access application. As part of the process, the
data moves to SQL Server 2005. Additionally, you can migrate other data sources,
such as Oracle and IBM DB2 into SQL Server 2005 for a centrally managed solution.
The advantage of this approach
The major advantage is the flexibility inherent in this approach. You create an
application that can target computers running Windows and the Web with minimum
changes. A more professional development environment, such as Visual Studio .NET,
offers advantages such as team-based management, source code control, and thirdparty tools and components. In this scenario, you have a reliable, scalable, and
manageable application that can move from the business unit to the enterprise level.
The disadvantage of this approach
The disadvantage of this approach is cost. Because you are discarding the Access
application and its database, you are creating a new application with a new design,
development, and implementation project. (Third-party products can help cut the
cost of front-end conversion. Consider using Access ConverterTM from Microtools.)
Implementation
Following is an example migration sequence:
1. Migrate the Access back-end schema and data. Use either SSMA Access or the
Upsizing Wizard (SSMA Access is preferable).
2. Migrate the Access forms to ASP.NET WebForms. Preserve the look and feel and
the operation of the original Access forms. All Access built-in features, such as
auto lookup, implicit updates, shortcuts, and tool tips can be emulated by using
advanced WebForms capabilities.
3. Convert Access queries to stored procedures. SSMA Access can help convert
SELECT queries.
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Guide to Migrating from Microsoft Access to SQL Server 2005
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4. The generated VB.NET code performs all database interactions and form
navigation. If necessary, convert that code to Visual C#®.NET with any number
of low-cost VB to C#.NET conversion tools.
5. Manually convert Microsoft Access VBA code to VB.NET or C#.NET. The time
required to migrate Visual Basic for Applications (VBA) code depends on the
volume and techniques employed. For example, applications that depend heavily
on the DAO (Data Access Objects) interface to perform database operations take
longer to convert than those that use built-in Access features.
Access Version Compatibility
Note that SSMA Access supports databases used in Access 97 and later. If you have
databases from an earlier version of Access, you must convert them to a newer
version. To convert, open and save the databases in Access 97 or a later version
before you add them to SSMA Access.
Migration Wizard
If you lack SSMA Access experience and need to migrate a single database, the SSM
Access Migration Wizard is the best choice for an easy and quick migration. You can
configure the Migration Wizard to run every time SSMA Access starts. The first
screen of the Wizard is shown in Figure 1.
Figure 1: The first screen of the Migration Wizard
To use the SSM Acess Migration Wizard to migrate databases
1. Step 1 of the wizard (see Figure 2), prompts for a name and location for your
new SSMA Access project. You can confirm the default values or enter your own.
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Guide to Migrating from Microsoft Access to SQL Server 2005
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Figure 2: Create a new project
2. Next, add databases to the project, as shown in Figure 3.
Figure 3: Add Access databases to the project
You can locate databases manually and add them to the list of databases to
migrate, or use the Find Database Wizard, shown in Figure 4, which makes
database selection easier.
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Guide to Migrating from Microsoft Access to SQL Server 2005
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Figure 4: Use the Find Databases Wizard for easier selection
3. Select the objects to migrate. Figure 5 shows the meta-base tree from which you
select objects to migrate.
Figure 5: Select objects for migration
4. Create a connection to SQL Server 2005, as shown in Figure 6. (If you lack the
information to create a connection to SQL Server 2005, contact your database
administrator.)
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Guide to Migrating from Microsoft Access to SQL Server 2005
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Figure 6: Connect to SQL Server 2005
5. You can migrate an Access database to an existing database as well as to a new
one. If the database you entered doesn't exist on the server running SQL Server,
SSMA Access prompts you to create it, as shown in Figure 7.
Figure 7: Prompt to create the specified database
6. The screen shown in Figure 8 asks whether to link tables. If you want access to
data stored on the SQL Server 2005 side, you need a link to SQL Server 2005
tables instead of to your Access objects. The operation changes the Access
database, but SSMA Access lets you link and unlink tables at any time.
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Guide to Migrating from Microsoft Access to SQL Server 2005
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Figure 8: The Migration Wizard asks whether to link tables
7. You can see the progress of the migration in the Migration Status window, shown
in Figure 9.
Figure 9: Check the migration progress
Figure 9 also shows the same steps you would follow to convert manually. The
Migration Wizard groups these actions into a single process that makes migration
easier and less error prone.
To check for errors during migration
1. SSMA Access converts database objects.
Check the Assessment report, shown in Figure 10, which reports all conversion
problems. For different views, change the window to display errors, warnings, or
information messages.
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Guide to Migrating from Microsoft Access to SQL Server 2005
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Figure 10: Check the Assessment report to view any problems
2. Load objects into the SQL database.
3. Migrate the data.
This generates the Data Migration report (Figure 11), which shows statistics
about each migrated table.
Figure 11: The Data Migration report shows statistics on each migrated
tables
4. Link SQL tables to the Access application.
Each step contains hyperlinks to show errors, warning, and information
messages. You can filter the message list by using buttons on the top of the
window, as shown in Figure 12.
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Figure 12: The Error List
You can continue working with project after the Migration Wizard finishes. Keep in
the mind that the Migration Wizard creates a new project each time you launch it.
Migrating Database Objects
This section looks at how to migrate Jet database objects by means of SSMA Access.
Setting the proper schema and type mapping is described first. After that, SSMA
Access conversion of constraints, indexes, and expressions is covered.
Schema Mapping
Your first migration step is to decide on the physical structure of the target SQL
Server 2005 database. In the simplest case, you can map the Access database to a
SQL Server 2005 database.
SSMA Access applies the selected schema-mapping method consistently when
converting database objects and references to them. You can change schema
mapping by using the Schema mapping tab for the database on the right of the
source schema tree. Click the Modify button to change the default mapping.
Figure 13: Choosing the target schema
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Guide to Migrating from Microsoft Access to SQL Server 2005
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After you choose your optimal schema mapping, you can start creating the target
SQL Server 2005 database and its required schemas.
The typical SSMA Access migration includes connecting to the source Access
database and the target SQL Server 2005, then running the Convert Schema
command. When the target objects are created in the SSMA Access workspace, you
can save them by using the Load to Database command.
Next, execute the Migrate Data command, which transfers the data from the
source to the target tables, making the necessary conversions. (The data migration
process is executed on the SQL Server 2005 computer.) Finally, run the Link
Tables command to link migrated tables to the Access application.
Each Access table is converted to a SQL Server 2005 table. All indexes and
constraints defined for each table are also converted. When determining the target
table's structure, SSMA Access uses type-mapping definitions.
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Type Mapping
The following table shows the default type mapping for migrating from Jet 4.0
(Access 2000 and later) to SQL Server 2005.
Size in bytes
(Jet 4.0)
Size * 2
Jet 4.0
SQL Server
2005
Possible Custom
Mapping
TEXT(size)
nvarchar(size)
Char(size), Varchar(size),
NChar(size), NVarchar(size),
Varchar(max), Nvarchar(max)
1073741823
MEMO
nvarchar(max)
Char(size), Varchar(size),
NChar(size), NVarchar(size),
Varchar(max), Nvarchar(max)
1
BYTE
tinyint
tinyint, smallint, int, bigint,
numeric(p,s), decimal(p,s),
float(p), double precision,
real, smallmoney, money
2
INTEGER
smallint
smallint, int, bigint,
numeric(p,s), decimal(p,s),
float(p), double precision,
real, smallmoney, money
4
LONG INTEGER
integer
smallint, int, bigint,
numeric(p,s), decimal(p,s),
float(p), double precision,
real, smallmoney, money
4
SINGLE
Real
numeric(p,s), decimal(p,s),
float(p), double precision,
real, smallmoney, money
8
DOUBLE
float
numeric(p,s), decimal(p,s),
float(p), double precision,
real, smallmoney, money
9
DECIMAL
float
tinyint, smallint, int, bigint,
numeric(p,s), decimal(p,s),
float(p), double precision,
real, smallmoney, money
16
GUID
uniqueidentifier
8
DATE
datetime
smalldatetime, datetime
8
CURRENCY
Money
numeric(p,s), decimal(p,s),
float(p), double precision,
real, smallmoney, money
2
YESNO
tinyint
tinyint, smallint, int, bigint
2147483647
LONGBINARY
varbinary(max)
image, binary, varbinary,
varbinary(max)
BINARY(size)
varbinary(size)
image, binary, varbinary,
varbinary(max)
Size
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The next table shows the default type mapping for migrating from Jet 3.5 (Access 97
and previous versions) to SQL Server 2005.
Size in bytes (Jet
3.5)
size
Jet 3.5
SQL Server
2005
Possible Custom Mapping
TEXT(size)
varchar(size)
Char(size), Varchar(size),
NChar(size), NVarchar(size),
Varchar(max),
Nvarchar(max)
1073741823
MEMO
varchar(max)
Char(size), Varchar(size),
NChar(size), NVarchar(size),
Varchar(max),
Nvarchar(max)
1
BYTE
tinyint
tinyint, smallint, int, bigint,
numeric(p,s), decimal(p,s),
float(p), double precision,
real, smallmoney, money
2
INTEGER
smallint
smallint, int, bigint,
numeric(p,s), decimal(p,s),
float(p), double precision,
real, smallmoney, money
4
LONG
INTEGER
integer
smallint, int, bigint,
numeric(p,s), decimal(p,s),
float(p), double precision,
real, smallmoney, money
4
SINGLE
real
numeric(p,s), decimal(p,s),
float(p), double precision,
real, smallmoney, money
8
DOUBLE
float
numeric(p,s), decimal(p,s),
float(p), double precision,
real, smallmoney, money
16
GUID
uniqueidentifier
8
DATE
datetime
smalldatetime, datetime
8
CURRENCY
money
numeric(p,s), decimal(p,s),
float(p), double precision,
real, smallmoney, money
2
YESNO
tinyint
tinyint, smallint, int, bigint
2147483647
LONGBINARY
varbinary(max)
image, binary, varbinary,
varbinary(max)
BINARY(size)
varbinary(size)
image, binary, varbinary,
varbinary(max)
Size
Type mapping can be defined for all databases and for each table separately by
using the Type mapping tab on the right of the source schema tree. To do this,
click the Edit button for the particular source type, as shown in Figure 14).
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Figure 14: Choosing the source type
Note Access and SQL Server 2005 have different default data types for
decimal without parameters. You must map the Access decimal data type to
SQL decimal(18, 2) (not just decimal) on the Type mapping tab.
Converting Schema Properties
This section has suggestions for converting a number of column attributes.
Default
Jet default expressions on columns are mapped to SQL Server 2005 default
expressions on columns.
Nullability
The Jet nullability column property is mapped directly to SQL Server 2005 NULL
column property.
Allow Zero Length
If the Allow zero length column property is set to false on text/memo columns in
Jet, it is mapped to a check constraint with a constraint name
"c_ssma_disallow_zero_length" on the varchar/nvarchar columns in SQL
Server 2005.
For example, the following code shows how to convert the Allow zero length
column property on column c1 in table table1:
Create table table1(c1 nvarchar(10),
c_ssma_disallow_zero_length
constraint
check(len(c1) >0))
Converting Constraints
This section describes how to convert the constraints of an Access table.
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Check Constraints
Check constraints (column-level or table-level) are expressions that should be
parsed and converted to SQL. (For details see Converting Expressions.)
Primary Keys
Jet primary keys are mapped directly to SQL Server 2005 primary keys.
Foreign Keys
Jet foreign keys are mapped directly to SQL Server 2005 foreign keys.
Exception:

SQL Server 2005 does not allow the Jet functionality of linking text and memo
columns with different size via a foreign key constraint. To overcome that, SSMA
Access schema type mapping is changed to enable the creation of the foreign
key constraint on the SQL Server 2005 side. Both columns participating in the
foreign key constraint are mapped to the same SQL Server 2005 type according
to the bigger Jet type.
Migrating Indexes
Jet indexes are mapped directly to SQL Server 2005 indexes.
Exceptions:

In cases where the MEMO column is indexed on the Jet side, the index is not
created on the SQL Server 2005 side since SQL Server 2005 does not support
indexing nvarchar (max) or varchar (max).

Tables that do not have a unique index and that do not have a primary key are
upsized, but an identity column is added to create a unique index.
Converting Expressions
To convert expressions, apply these rules in sequence:
1. Remove any leading = character in a Jet expression. For example:
Create table foo(x1 int default =5)
in Jet is converted to
Create table foo(x1 int 5)
for SQL Server 2005.
2. Replace a double quote (") with a single quote ('). For example: "abc" in Jet is
converted to 'abc' for SQL Server 2005.
3. Double any embedded single quotes. For example: "a'a" in Jet is converted to
'a"'c' for SQL Server 2005. The quote in the middle of "a'a" is doubled to create
'a"c'.
4. Replace # around dates with single quotes. For example #1/6/2006# in Jet is
converted to '1/6/2006' for SQL Server 2005.
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17
5. Replace the function tokens found inside the expression according to the
following table.
Jet function token Replace with SQL Server 2005 function token
Yes
-1
On
-1
True
-1
No
0
Off
0
False
0
Mod
%
Sgn(
Sign(
chr(
Char(
Chr$(
Char(
Asc(
ascii(
str$(
str(
int(
floor(
Cint(
convert(smallint,
Clng(
convert(int,
csng(
convert(real,
cdbl(
convert(float,
Cstr(
convert(varchar,
ccur(
convert(money,
cvdate(
convert(datetime,
space$(
space(
lcase(
lower(
lcase$(
lower(
ucase(
upper(
ucase$(
upper(
len(
datalength(
Ltrim$(
Ltrim(
Rtrim$(
Rtrim(
Right$(
Right(
Mid(
substring(
Mid$(
substring(
Now()
getdate()
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Jet function token Replace with SQL Server 2005 function token
Date()
convert(datetime,convert(varchar,getdate(),1))
year(
datepart(yy,
month(
datepart(mm,
Day(
datepart(dd,
weekday(
datepart(dw,
Hour(
datepart(hh,
minute(
datepart(mi,
second(
datepart(ss,
time()
convert(datetime, convert(varchar,getdate(),14))
6. Use the next table to replace the format tokens inside datepart(),dateadd()
datediff() functions.
Jet strings format part of
datepart(),dateadd() datediff() functions
Replace with SQL
Server 2005 format
"yyyy"
Yy
"q"
Qq
"m"
Mm
"y"
Dy
"d"
Dd
"w"
Dw
"ww"
Wk
"h"
Hh
"n"
Mi
"s"
Ss
"yy"
Yy
"qq"
Qq
"mm"
Mm
"dy"
Dy
"dd"
Dd
"dw"
Dw
"wk"
Wk
"hh"
Hh
"mi"
Mi
"ss"
Ss
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Handling Timestamps
After you upsize the performance of record editing, performance may degrade for
some column types. This is because Access must check whether each column was
changed before committing the changed data. To fix this, add a timestamp column
by using SSMA. You can control this addition in Project Settings, as shown in
Figure 15.
Figure 15: Adjust timestamp handling in Project Settings
Naming
SQL Server 2005 supports spaces and nonalphanumeric characters in object names,
as long they are surrounded by square brackets in DDL statements.
Table Migration Potential Problems
This section covers typical situations in which migration problems can arise. It
includes SSMA Access handling or user solutions.
Access Table Does Not Have Unique Index or
Primary Key

If a table without a unique index is upsized, it will be uneditable after the
upsizing.

If the table does not have a primary key or unique index, the destination script
displays the following message:
"Table <table name> does not have a primary key or unique index and
therefore cannot be edited from within Access."

If the table does not have an auto number index, SSMA Access can automatically
create a new column called ssma_rowid and create a primary key on that
column. You will see the following warnings in the destination code:

"A new identity column 'SSMA_RowID' was created for the primary key."

"Primary key 'SSMA_PK$Table1' was created for the identity column."
You can enable or disable the automatic generation of a primary key column in
Project Settings, as shown in Figure 16.
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Figure 16: Create a primary key in Project Settings
Access Table Unique Index Contains Multiple Null
Values
Data containing multiple null values in an Access table column that has a unique
index cannot be transferred to SQL Server 2005. This is because a SQL Server 2005
unique index does not allow multiple nulls. During data migration you will receive
the following error message:
"Cannot insert duplicate key row in object <table name> with unique index
<index name>."
Primary Key Includes Columns That Allow Null
Values
In Access, a primary key can include columns with the Required field set to false.
This is not allowed in SQL Server 2005. By default, SSMA Access produces the
following warning:
"Column <column name> of the primary key is nullable, which SQL Server
2005 does not allow. The nullable flag was removed from the target column
to avoid problems during loading database objects into SQL Server 2005. If
there are rows that contain NULL values, you might encounter problems
during data migration."
Control SSMA behavior in this situation with Project Settings, as shown in Figure 17.
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Figure 17: Warn when the primary key includes nullable columns
Your choices are:

Warning: (Set by default.) All columns with a NOT NULL attribute will form the
primary key.

Error: SSMA Access generates an error and does not convert the table.

No message: Tables are converted as is, ignoring possible application problems.
Access Table Contains Dates Out of SQL Server
Range
The SQL Server 2005 datetime type accepts dates only in the range of 1 Jan 1753
to 31 Dec 9999. Access, in contrast, accepts dates in the range of 1 Jan 100 to
31 Dec 9999. This can cause data transfer to fail. SSMA Access changes an incorrect
value to nearest date limit. For example, SSMA Access migrates 1/01/1700 as
1/01/1753.
Access Table Contains Boolean Fields With Null
Values
After linking a table that has Boolean fields containing nulls, the table cannot be
edited in Access. SSMA Access displays the following warning:
"The bit column 'Checked' has no default value. To avoid problems with null
values in Access applications, the default value '0' was added to target
column"
Access Objects Have the Same Names as
SQL Server Keywords
SQL Server 2005 can accept objects (such as tables, columns, indexes, schemas)
that have the same names as SQL Server 2005 keywords—if you surround the
object names with quotation marks in the DDL statement. All queries that reference
these objects must include the quotation marks around names as well. Therefore,
Access queries that use names without quotation marks can fail.
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SSMA Access tries to avoid the problem by adding square brackets and displaying
the warning message:
"Column <column name> has a name that might cause problems for the
Access application to function correctly against SQL Server 2005."
Access Objects Names Include Special
Characters
SQL Server 2005 can accept object (for example, tables, columns, indexes,
schemas) names that include special characters (space, &, +, *) if you surround the
names with quotation marks in the DDL statement. All queries that reference these
objects must include the quotation marks around names as well. That means that it
is possible that Access queries that do not have the quotation marks will fail.
SSMA Access tries to avoid the problem by adding square brackets and displaying
the warning message:
"Column <column name> has a name that might cause problems for the
Access application to function correctly against SQL Server 2005."
Hyperlink Column Jump Functionality Is Lost
After Upsizing
After upsizing, Jet hyperlink columns are treated the same as regular memo columns
and loose their jump functionality. This is because the hyperlink is a Jet column flag
that is read from SQL Server 2005 after the upsizing. Since SQL does not have that
flag, the information is lost. In this situation SSMA Access displays the following
warning:
"The hyperlink column <column name> was converted to a text column and,
as a result, is no longer a link."
Memo Column Is Indexed in Access
Access supports indexing the memo column, but SQL Server 2005 does not support
indexing nvarchar(max). If you use the default type mapping, SSMA Access
displays the following warning:
"Index <column name> is on a memo column and cannot be created on SQL
Server 2005 with the current type mapping settings."
Figure 18 shows how to control this situation in Project Settings (similar to the way
you handle primary keys with nulls).
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Figure 18: Options for handling index memo columns
Jet Syntax Potential Problems
The current version of SSMA Access can convert only SELECT statements into
Transact-SQL views. INSERT, UPDATE, and DELETE query conversion is not
implemented. This section describes the syntax difference between the two
platforms.
If SSMA Access can handle an issue, it is marked with "SSMA Access support = Yes"
in the statement descriptions in this section and the solution is explained. If SSMA
Access cannot make the automatic conversion, the solution for manual handling is
included.
SELECT Statement
This section describes how some incompatible clauses of the SELECT
statement can be handled during the migration.
Distinctrow Keyword
Issue: Jet SQL can use the Distinctrow keyword, but Transact-SQL doesn't have
such a keyword.
SSMA Access support:Yes
Solution:Emulate with a subquery.
Example:
Jet
SELECT Distinctrow <FieldsList> FROM Table
SQL Server 2005
SELECT <FieldsList> FROM (SELECT distinct * FROM Table) Table
Select Into Another Database
Issue: Jet SQL syntax is different from Transact-SQL.
SSMA Access support: No
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Solution: Modify syntax so that it is more like Transact-SQL.
Example:
Jet
SELECT Suppliers.* INTO Suppliers IN 'Backup.mdb' FROM Suppliers;
SQL Server 2005
SELECT Suppliers.* INTO BackupDB..Suppliers FROM Suppliers;
Incompatible Use of Alias
Issue: Jet SQL allows the use of an alias in the same statement in which it is
defined.
SSMA Access support: No
Solution: Use the full expression instead of an alias.
Example:
Jet
SELECT (Price * discount) AS saving, (Price – saving) AS NewPrice FROM
Products
SQL Server 2005
SELECT (Price * discount) AS saving, (Price – Price * discount) AS
NewPrice FROM Products
Logical Expressions in a Select Statement
Issue: Jet SQL interprets two expressions with = between them in the SELECT
statement as Boolean expressions.
SSMA Access support: Yes
Solution: Use a CASE statement to emulate similar behavior. Keep in the mind that
the Boolean type in the Access has the numeric value -1.
Example 1:
Jet
SELECT Sum(discount = 0.8) FROM Products
SQL Server 2005
SELECT Sum(Case discount when 0.8 then -1 Else 0) FROM Products
Example 2:
Jet
SELECT Sum(<logical expression>) FROM Products
SQL Server 2005
SELECT Sum(CASE when <logical expression> then -1 ELSE 0) FROM Products
TOP N Clause
Issue: Jet SQL calls the TOP operator using WITH TIES by default.
SSMA Access support: Yes
Solution: Add WITH TIES to the Transact-SQL statement.
Example:
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Jet
SELECT top 3 * FROM Products Order by SomeField
SQL Server 2005
SELECT top 3 With Ties * FROM Products Order by SomeField
Multiple Dot Syntax
Issue: Jet SQL allows multiple dot identifiers.
SSMA Access support: No
Solution: Add aliases to all fields and use these aliases in the top-level query.
Example:
Jet
SELECT x.a.AAAA, x.b.AAAA FROM [SELECT a.AAAA, b.AAAA FROM table1 a
Inner Join Table2 b On a.ID = b.ID]. AS x
SQL Server 2005
SELECT x.Field1, x.Field2 FROM [SELECT a.AAAA as Field1, b.AAAA as
Field2 FROM table1 a Inner Join Table2 b On a.ID = b.ID]. AS x
Common Syntax Constructs
This section covers converting incompatible operators in the SELECT
statement expressions.
Expressions
Access Jet SQL has expressions similar to Transact-SQL expressions. Most operators
can move to SQL Server 2005 without any conversion. These include comparison
operators (<, >, =, >=, <=, <>, between), logical operators (And, Or, Xor), and
arithmetic operators (+, -, *, /). The others are described next.
'&' as Concatenation Operator
Issue: Jet can use & as a string concatenation operator while SQL Server 2005 uses
only the + character for string concatenation.
SSMA Access support: No
Solution: Convert any & character used for concatenation to + in SQL Server 2005.
Example:
Jet
SELECT * FROM table1 WHERE c1 = 'a' & 'b'
SQL Server 2005
SELECT * FROM table1 WHERE c1 = 'a' + 'b'
'\' Operator (Integer Division)
Issue: Jet has an integer division operator, but Transact-SQL does not.
SSMA Access support: No
Solution: Use just the division operator /, but make Dividend and Divisor
rounded and reduced to an integer type.
Example:
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Jet
a \ b
SQL Server 2005
Cast(Round(@a, 0) as int) / Cast(Round(@b, 0) as int)
'Mod' Operator (Modulus Division)
Issue: Jet has a different operator for modulus division.
SSMA Access support: Yes
Solution: Use the Transact-SQL operator % but Dividend and Divisor should be
rounded and reduced to an integer type.
Example:
Jet
a mod b
SQL Server 2005
Cast(Round(@a, 0) as int) % Cast(Round(@b, 0) as int)
'^' Operator (Raise to Power)
Issue: Jet has a different operator to raise to a power.
SSMA Access support: Yes
Solution: Use the Transact-SQL function Power(a, b) to emulate the expression.
Example:
Jet
a ^ b
SQL Server 2005
Power(@a, @b)
'Eqv' and 'Imp'
Issue: Transact-SQL does not have Eqv nor Imp operators.
SSMA Access support: Yes
Solution: Emulate these expressions. But because Transact-SQL does not have
Boolean variables, you must convert boolean values into bit.
Example 1
Jet
SELECT (a > b) eqv (b < c)
SQL Server 2005
SELECT CASE (Case when a > b Then 1 else 0 end) WHEN (Case
WHEN b < c Then 1 else 0 end) then 1 ELSE 0 END
Example 2
Jet
SELECT (a > b) imp (b < c)
SQL Server 2005
SELECT CASE (Case when a > b Then 1 ELSE 0 END) WHEN (Case
WHEN b < c Then 1 else 0 end) then 1 ELSE 0 END
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Example 3
Jet
SELECT * From SomeTable where (a > b) eqv (b < c)
SQL Server 2005
SELECT * From SomeTable Where (Case when a > b Then 1 ELSE
0 end) = (Case when b < c Then 1 ELSE 0 END)
Example 4
Jet
SELECT * From SomeTable where (a > b) imp (b < c)
SQL Server 2005
SELECT * From SomeTable Where (Case when a > b Then 1 ELSE 0
end) <> (Case when b < c Then 1 ELSE 0 END)
Date Literals Declaration
Issue: Jet SQL encloses date literals in # symbols, but SQL Server 2005 can only
use ' (apostrophe).
SSMA Access support: Yes
Solution: Replace # symbol with ' (apostrophe) in the date literals.
Example:
Jet
#03-22-2006#
SQL Server 2005
'03-22-2006'
Like Operator
Issue: Jet SQL has two Like operators: Alike and Like. The former works with SQL
Server 2005 Compatible Syntax (ANSI 92) (in Access 2002 and later versions).
Replace it with the Like keyword during conversion to SQL Server 2005. The latter
has different syntax in patterns.
SSMA Access support: Yes
Solution: Replace the keyword alike with like, or modify the pattern according to
the following table.
Jet SQL
Transact-SQL
?
_
#
[0-9]
*
%
[<charlist>]
[<charlist>]
[!<charlist>]
[^<charlist>]
^
\ (backslash)
In the table, <charlist> is a sequence of characters (such as ABC) or a character
range (A-Z).
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Example:
Jet
a like '1234*', a alike '1234%' (in the Access 2002 and
higher)
SQL Server 2005
@a like '1234%'
Join to View Converting Issues
Converting Access Query with Joins to SQL View can result in a problem with field
name duplication. For example:
Create view SomeView
As
Select a.Fleld1, b.field1
From a Inner join b On a.ID = b.ID
To avoid this, add aliases to the query field:
CREATE view SomeView
AS
SELECT a.Fleld1 AS a_Field1, b.field1 AS b_Field1
FROM a Inner join b On a.ID = b.ID
Transform…Pivot Statement
The solutions for converting TRANSFORM…PIVOT statements use a source statement
in the following form as an example:
TRANSFORM "aggfunction"
"selectstatement"
PIVOT "pivotfield" [IN ("value1"[, "value2"[, ...]])]
The following code examples show ways to convert these statements into
Transact-SQL commands. All three example cases assume that the parameter
aggfunction is neither the First() nor Last() function.
Case 1. The PIVOT clause contains IN(…) part.
Convert the following statement:
TRANSFORM aggrfunction(Col1)
SELECT <Col3,..., ColN> FROM Table AS t
GROUP BY <Col3,..., ColN>
ORDER BY <Column list>
PIVOT (Col2)
in (<col2_value1,col2_value2,...,col2_valueN>)
To the following code:
SELECT * FROM (
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SELECT <Col3,..., ColN>,Col1,Col2 FROM Table ) T
PIVOT
(
aggrfunction (Col1) FOR Col2
IN([col2_value1],[col2_value2],...,[col2_valueN])
) T
ORDER BY <Column list>
Case 2. The PIVOT clause does not contain IN(…) part and Col2 data type is
a natural number.
Convert the following statement:
TRANSFORM aggrfunction(Col1)
SELECT <Col3,..., ColN> FROM Table AS t
GROUP BY <Col3,..., ColN>
ORDER BY <Column list>
PIVOT (Col2);
To the following code:
declare
@colunm_list nvarchar(max)
SET @colunm_list= ''
SELECT @colunm_list=@colunm_list+
CASE when rnum = 1 then quotename(ID)
ELSE ',' +quotename(ID)
END
FROM (SELECT ROW_NUMBER() over(order by ID asc) as rnum, id
FROM (SELECT distinct(Col2) as ID FROM "Table"
)T
) t1
exec ('
SELECT * FROM (
SELECT <Col3,..., ColN>,Col1,Col2 FROM "Table"
) T
PIVOT
(aggrfunction(Col1) FOR Col2 N('+@colunm_list+')
) T
ORDER BY <Column list>')
Case 3. The PIVOT clause does not contain IN(…) part and Col2 data type is
a real number.
Access replaces , in real numbers with _.
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TRANSFORM aggrfunction(Col1)
SELECT <Col3,..., ColN> FROM Table AS t
GROUP BY <Col3,..., ColN>
ORDER BY <Column list>
PIVOT (Col2);
The following code emulates this Access feature:
declare
@colunm_list nvarchar(max)
SET @colunm_list= ''
SELECT @colunm_list=@colunm_list+
CASE when rnum = 1 then quotename(replace(cast(ID
asvarchar(100)),'.','_'))
ELSE ',' +quotename(replace(cast(ID AS varchar(100)),'.','_'))
END
FROM ( SELECT ROW_NUMBER() over(order by ID asc) AS rnum, id
FROM ( SELECT distinct(Col2) AS ID FROM
"Table"
)T
) t1
exec ('
SELECT * FROM (
SELECT <Col3,..., ColN>,Col1,
REPLACE(cast(Col2 as varchar(100)),'.','_') as Col2 FROM
"Table"
) T
PIVOT
(
aggr_function(Col1) FOR Col2 IN('+@colunm_list+')
) T
ORDER BY <Column list>')
Functions
Many standard Access functions have no direct correspondence in SQL Server 2005.
This section gives guidance on converting these functions.
If SSMA Access can handle a potential problem, the explanations for each function
are marked: "SSMA Access support = Yes" and the solution is explained. If SSMA
Access cannot make the automatic conversion, the solution for manual handling is
included.
String Functions
Some string functions can be moved to SQL Server 2005 without any modification,
including Left[$](), Right[$](), LTrim[$](), RTrim[$](), Space[$](), Len().
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31
Some string functions can have $ at the end of the name. They can be skipped.
Issue: The Jet ASC function returns the NUMBER code that represents the specific
character. SQL Server 2005 has the ASCII function with similar functionality.
SSMA Access support: Yes
Solution: Replace the ASC function with ASCII.
Example:
Jet
ASC('A')
SQL Server 2005
ASCII('A')
Issue: The Jet CHR function returns the character based on the NUMBER code.
Transact-SQL has the CHAR function with similar functionality.
SSMA Access support: Yes
Solution: Replace the CHR and CHR$ functions with CHAR.
Example:
Jet
CHR[$](65)
SQL Server 2005
CHAR(65)
Issue: The Jet LCASE function converts a string to lower case. The Transact-SQL
LOWER function has similar functionality.
SSMA Access support: Yes
Solution: Replace the LCASE and LCASE$ functions with LOWER.
Example:
Jet
LCASE[$]('ABCDEFG')
SQL Server 2005
LOWER('ABCDEFG')
Issue: The Jet UCASE function converts a string to all upper case. The UPPER
Transact-SQL has a function has similar functionality.
SSMA Access support: Yes
Solution: Replace UCASE with UPPER.
Example:
Jet
UCASE[$]('abcdefg')
SQL Server 2005
UPPER('abcdefg')
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32
Issue: The Jet LEFT function extracts a substring from a string, starting from the
leftmost character. Transact-SQL has a function with the same name and similar
functionality.
SSMA Access support: Yes
Solution: Remove the $ character if it is in the function name.
Example:
Jet
LEFT[$]('String', Number)
SQL Server 2005
LEFT('String', Number)
Issue: The Jet RIGHT function extracts a substring from a string starting from the
right-most character. Transact-SQL has a function with the same name and similar
functionality.
SSMA Access support: Yes
Solution: Remove the $ character if it is in the function name.
Example:
Jet
RIGHT[$]('String', Number)
SQL Server 2005
RIGHT('String', Number)
Issue: The Jet LTRIM function removes leading spaces from a string. Transact-SQL
has a function with the same name and similar functionality.
SSMA Access support: Yes
Solution: Remove the $ character if it is in the function name.
Example:
Jet
LTRIM[$]('String')
SQL Server 2005
LTRIM('String')
Issue: The Jet RTRIM function removes trailing spaces from a string. Transact-SQL
has a function with the same name and similar functionality.
SSMA Access support: Yes
Solution: Remove the $ character if it is in the function name.
Example:
Jet
RTRIM[$]('String')
SQL Server 2005
RTRIM('String')
Issue: The Jet LEN function returns the length of the specified string. Transact-SQL
has a function with the same name and similar functionality.
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SSMA Access support: Yes
Solution: No changes required.
Example:
Jet
LEN('String')
SQL Server 2005
LEN('String')
Issue: The Jet SPACE function returns a string with a specified number of spaces.
Transact-SQL has a function with the same name and similar functionality.
SSMA Access support: Yes
Solution: Remove the $ character if it is in the function name.
Example:
Jet
SPACE[$](Number)
SQL Server 2005
SPACE(Number)
Issue: The Jet STR function returns a string representation of a number. TransactSQL has a function STR but it works differently. Use LTRIM() with STR() or use
CAST().
SSMA Access support: Yes
Solution: Add the LTRIM function or replace the STR function with CAST.
Example:
Jet
STR[$](123456)
SQL Server 2005
LTRIM(STR(123456)) Or CAST(123456 as vachar)
Issue:
The Jet TRIM() function removes leading and trailing spaces from a string. TransactSQL does not have such a function, but you can emulate it by using
LTRIM(RTRIM()).
SSMA Access support: Yes
Solution: Replace the TRIM function with LTRIM and RTRIM.
Example:
Jet
TRIM[$]("
asdf ")
SQL Server 2005
LTRIM(RTRIM('
asdf '))
Issue: Jet SQL has the FORMAT function but Transact-SQL does not have anything
similar.
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34
SSMA Access support: No
Solution: Write a UDF to emulate this function.
Example:
Jet
FORMAT("12345.678", "#, ##0.00")
SQL Server 2005
No equivalent (emulated as UDF Format_*)
Issue: The Jet INSTR function returns the position of the first occurrence of a string
in another string. The CHARINDEX Transact-SQL function has similar functionality.
SSMA Access support: Yes (partial)
Solution: Replace the INSTR function with CHARINDEX for the cases shown in the
following code examples. Keep in mind that the optional parameter start position is
first in the Access function definition. The conversion depends on the format of
INSTR.
Format 1:
Jet
INSTR(String, subString)
SQL Server 2005
CHARINDEX(substring String)
Format 2:
Jet
INSTR(startposition, String, subString)
SQL Server 2005
CHARINDEX(substring, String, startposition)
Format 3:
Jet
INSTR(startposition, String, subString, ComparisionType)
SQL Server 2005
no equivalent
Format 4:
Jet
INSTR(String, subString, ComparisionType)
SQL Server 2005
no equivalent
Issue: The Jet MID function extracts a substring from a string (starting at any
position). The Transact-SQL SUBSTRING function has similar functionality.
SSMA Access support: Yes
Solution: Replace the MID function with SUBSTRING.
Example:
Jet
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35
MID[$](String, StartPosition, numberOfChararcters)
SQL Server 2005
SUBSTRING(String, StartPosition, numberOfChararcters)
Example 2:
Jet
MID[$](String, StartPosition)
SQL Server 2005
SUBSTRING(String, StartPosition, Len('String') –
StartPosition + 1)
Issue: The Jet REPLACE function replaces a sequence of characters in a string with
another set of characters. Transact-SQL has the same function with similar
functionality.
SSMA Access support: Yes (partial)
Solution: Keep the REPLACE function for the cases shown in the following code
examples. The conversion depends on the format of the original call.
Format 1:
Jet
REPLACE(String, Find, Replacement)
SQL Server 2005
REPLACE (String, Find, Replacement)
Format 2:
Jet
REPLACE(String, Find, Replacement, Start)
SQL Server 2005
Replace(SubString(String, Start, Len(String) - start + 1),
Find,Replacement)
Format 3:
Jet
REPLACE(String, Find, Replacement, Start, Count)
SQL Server 2005
no equivalent (emulated as UDF Replace5)
Format 4:
Jet
REPLACE(String, Find, Replacement, Start, Count,
ComparisionType)
SQL Server 2005
no equivalent
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Issue: Jet SQL has the STRCONV function, but Transact-SQL does not have
anything similar.
SSMA Access support: No
Solution: Write a UDF to emulate this function.
Example:
Jet
STRCONV(Text, ConversionType[, LCID])
SQL Server 2005
No equivalent
Advanced Functions
Issue: The Jet SQL ISDATE function returns TRUE if the expression is a valid date.
Otherwise, it returns FALSE. Transact-SQL has the ISDATE function but it doesn't
have a Boolean type. Therefore, the function syntax is slightly different.
SSMA Access support: Yes
Solution: The SQL Server function returns an integer value (not Boolean).
Therefore, it should be checked explicitly.
Example:
Jet
ISDATE(expression)
SQL Server 2005
ISDATE(expression) <> 0
Issue: The Jet SQL ISNULL function returns TRUE if the expression is a null value.
Otherwise, it returns FALSE. Transact-SQL has the ISNULL function, but it has
another function.
SSMA Access support: Yes
Solution: Use the SQL Server is null expression.
Example:
Jet
ISNULL(expression)
SQL Server 2005
expression is null
Issue: The Jet SQL ISNUMERIC function returns TRUE if the expression is a valid
number. Otherwise, it returns FALSE. Transact-SQL has the ISNUMERIC function but
it does not have a Boolean type. Therefore, the syntax of the function call is slightly
different.
SSMA Access support: Yes
Solution: The SQL Server function returns an integer value (not Boolean), so the
comparison with 0 (zero) should be added in WHERE conditions.
Example 1:
Jet
Select * From SomeTable Where ISNUMERIC(expression)
SQL Server 2005
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Select * From SomeTable Where ISNUMERIC(expression) <> 0
Example 2:
Jet
Select ISNUMERIC(expression)
SQL Server 2005
Select ISNUMERIC(expression)
Issue: The Jet NZ function lets you return a value when a variant is null. The
Transact-SQL ISNULL function has similar functionality.
SSMA Access support: Yes
Solution: Replace the NZ function with ISNULL.
Example 1:
Jet
NZ(expression1, expression2)
SQL Server 2005
ISNULL(expression1, expression2)
Example 2:
Jet
NZ(expression1)
SQL Server 2005
ISNULL(expression1, '')
Issue: The Jet IIF function returns one value if a specified condition evaluates to
TRUE, and another value if it evaluates to FALSE. Transact-SQL does not have a
similar function, but it can be emulated by using a CASE statement.
SSMA Access support: Yes
Solution: Emulate the IIF function with a CASE statement.
Example:
Jet
IIF(condition, statement_if_true [, statement_if_false])
SQL Server 2005
CASE WHEN condition THEN statement_if_true [ELSE statement_if_false]
END
Issue: The Jet SWITCH function evaluates a list of expressions and returns the
corresponding value for the first expression in the list that is TRUE. Transact-SQL
does not have such a function, but it can be emulated with a CASE statement.
SSMA Access support: No
Solution: Emulate the SWITCH function with a CASE statement.
Example:
Jet
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Guide to Migrating from Microsoft Access to SQL Server 2005
38
SWITCH(condition1, statement1 … [,conditionN, statementN])
SQL Server 2005
CASE WHEN condition1 THEN statement1 … [ WHEN conditionN THEN
statementN ] ELSE null END
Issue: Jet SQL has the CHOOSE function, but Transact-SQL does not have anything
similar.
SSMA Access support: No
Solution: Write a UDF to emulate this function.
Example:
Jet
Choose(position, value1, value2, ... value_n )
SQL Server 2005
No equivalent
Issue: The Jet SQL CURRENTUSER function returns the name of the current Access
user. The Transact-SQL CURRENT_USER function has similar functionality.
SSMA Access support: Yes
Solution: Replace the CURRENTUSER function with CURRENT_USER.
Example:
Jet
CURRENTUSER()
SQL Server 2005
CURRENT_USER
Domain Aggregate Functions
Access has the domain aggregate functions (DAvg, DCount, DFirst, DLast,
DLookup, DMin, DMax, DSum). Their main syntax is:
DFunctionName(expression, domain [, criteria])
SSMA Access support:
No. These functions can be converted in common cases into SELECT statements as
dynamic SQL only as in the following code:
Declare @Str Varchar(1000)
Set @Str = 'SELECT FunctionName(' + expression
' Where ' +
+ ') FROM ' + domain +
<criteria>
Exec (@Str)
The correspondence between Access functions and SQL Server 2005 functions is
shown in the following table.
Jet Function (DFunctionName)
DAvg()
SQL Server 2005
(FunctionName)
Avg()
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Guide to Migrating from Microsoft Access to SQL Server 2005
Jet Function (DFunctionName)
39
SQL Server 2005
(FunctionName)
DCount()
Count()
DFirst()
No equivalent
DLast()
No equivalent
DLookup()
Skipped (use only expression in
SELECT clause)
DMin()
Min()
DMax()
Max()
DSum()
Sum()
Numeric/Mathematical Functions
You can move some numeric/mathematical functions to SQL Server 2005 without
any modification, such as Abs(), Avg(), Cos(), Exp(), Log(), and Round().
Issue: The Jet ABS function returns the absolute value of a number. Transact-SQL
has a function with the same name and similar functionality.
SSMA Access support: Yes
Solution: No changes required.
Example:
Jet
ABS(ABC)
SQL Server 2005
ABS(@ABC)
Issue: The Jet ATN function returns the arctangent of a number. The Transact-SQL
ATAN function has similar functionality.
SSMA Access support: Yes
Solution: Replace ATN with ATAN.
Example:
Jet
ATN(ABC)
SQL Server 2005
ATAN(@ABC)
Issue: The Jet COS function returns the cosine of an angle. Transact-SQL has a
function with the same name and similar functionality.
SSMA Access support: Yes
Solution: No changes needed.
Example:
Jet
COS(ABC)
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40
SQL Server 2005
COS(@ABC)
Issue: The Jet EXP function returns e raised to the nth power, where
e = 2.71828183. Transact-SQL has a function with the same name and similar
functionality.
SSMA Access support: Yes
Solution: No changes required.
Example:
Jet
EXP(ABC)
SQL Server 2005
EXP(@ABC)
Issue: The Jet FIX function returns the integer portion of a number. Transact-SQL
does not have a similar function, but you can emulate it by using CAST().
SSMA Access support: Yes
Solution: Replace FIX with CAST.
Example:
Jet
FIX(123.456)
SQL Server 2005
CAST(123.456 as integer)
Issue:
The Jet INT function returns the integer portion of a number. The Transact-SQL
FLOOR function has similar functionality.
SSMA Access support: Yes
Solution: Replace INT with FLOOR.
Example:
Jet
INT(123.456)
SQL Server 2005
FLOOR(123.456)
Issue: Jet has the LOG function. Transact-SQL has a function with the same name
and similar functionality.
SSMA Access support: Yes
Solution: No changes needed.
Example:
Jet
LOG(ABC)
SQL Server 2005
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41
LOG(@ABC)
Issue: Jet has the RND function. The Transact-SQL RAND function has similar
functionality.
SSMA Access support: Yes
Solution: Replace RND with RAND().
Example:
Jet
RND
SQL Server 2005
RAND()
Issue: The Jet ROUND function returns a number rounded to a specified number of
decimal places. Transact-SQL has a function with the same name and similar
functionality. But the absence of the second parameter in SQL Server 2005 is not
allowed.
SSMA Access support: Yes
Solution: If the second parameter is absent, in SQL Server 2005 specify the value
0 (zeo) for the second parameter of the ROUND function.
Example:
Jet
ROUND(ABC, 2)
SQL Server 2005
ROUND(@ABC, 2)
Issue: The Jet SIN function returns the sine of an angle. Transact-SQL has a
function with the same name and similar functionality.
SSMA Access support: Yes
Solution: No changes required.
Example:
Jet
SIN(ABC)
SQL Server 2005
SIN(@ABC)
Issue: The Jet SGN function returns the sign of a number (represented as an
integer). The Transact-SQL SIGN function has similar functionality.
SSMA Access support: Yes
Solution: Replace SGN with SIGN.
Example:
Jet
SGN(123.456)
SQL Server 2005
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42
SIGN(123.456)
Issue: The Jet TAN function returns the tangent of a number. Transact-SQL has a
function with the same name and similar functionality.
SSMA Access support: Yes
Solution: No changes required.
Example:
Jet
TAN(ABC)
SQL Server 2005
TAN(@ABC)
Issue: Jet SQL has the VAL function, but Transact-SQL does not have anything
similar. VAL accepts a string as input and returns the numbers found in that string.
SSMA Access support: No
Solution: Write a UDF to emulate this function.
Example:
Jet
VAL ("
34
10 Main Street ")
SQL Server 2005
No equivalent
Date Functions
Some Access date functions use date parts. To convert them to SQL Server 2005
definitions, use the following table.
Access definition
Explanation
SQL Server 2005 possible
equivalents
'yyyy'
Year
year, yyyy, yy
'q'
Quarter
quarter, q, qq
'm'
Month
month, mm, mm
'y'
Day of the year
dayofyear, dy, y
'd'
Day
day, dd,. D
'w'
Weekday
weekday, dw
'ww'
Week
week, wk, ww
'h'
Hour
hour, hh
'n'
Minute
minute, mi, n
's'
Second
second, ss, s
You can convert some functions to SQL Server 2005 according to the table
(DateAdd(), DateDiff(), DatePart()), but they have more advanced functionality
in Access. If you do not have additional parameters, you can convert them according
to the previous table.
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43
Some Access date functions, such as Day(), Month(), Year(), can be moved into
SQL Server 2005 without any modification.
Issue: The Jet DATEADD function returns a date after which a certain time/date
interval has been added. SQL has a function with the same name and similar
functionality.
SSMA Access support: Yes
Solution: Replace the Jet SQL interval definition with a Transact-SQL one.
Example:
Jet
DATEADD('interval', Number, date)
SQL Server 2005
DATEADD(interval, Number, date)
Issue: The Jet DATEDIFF function returns the difference between two date values,
based on the interval specified. Transact-SQL has a function with the same name
and similar functionality.
SSMA Access support: Yes
Solution: Replace the Jet SQL interval definition with a Transact-SQL one.
Example:
Jet
DATEDIFF('interval', date1, date2)
SQL Server 2005
DATEDIFF(interval, date1, date2)
Issue: The Jet DATEPART function returns a specified part of a given date.
Transact-SQL has a function with the same name and similar functionality.
SSMA Access support: Yes
Solution: Replace the Jet SQL interval definition with a Transact-SQL one.
Example:
Jet
DATEPART('interval', date)
SQL Server 2005
DATEPART(interval, date)
Issue: The Jet DAY function returns the day of the month (a number from 1 to 31)
given a date value. Transact-SQL has a function with the same name and similar
functionality.
SSMA Access support: Yes
Solution: No changes required.
Example:
Jet
DAY(date)
SQL Server 2005
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Guide to Migrating from Microsoft Access to SQL Server 2005
44
DAY(date)
Issue: The Jet MONTH function returns the month (a number from 1 to 12) given a
date value. Transact-SQL has a function with the same name and similar
functionality.
SSMA Access support: Yes
Solution: No changes required.
Example:
Jet
MONTH(date)
SQL Server 2005
MONTH(date)
Issue: The Jet YEAR function returns a four-digit year (a number from 1900 to
9999) given a date value. Transact-SQL has a function with the same name and
similar functionality.
SSMA Access support: Yes
Solution: No changes required.
Example:
Jet
YEAR(date)
SQL Server 2005
YEAR(date)
Issue: The Jet NOW function returns the current system date and time. The
Transact-SQL GETDATE function has similar functionality.
SSMA Access support: Yes
Solution: Replace NOW with GETDATE.
Example:
Jet
NOW()
SQL Server 2005
GETDATE()
Issue: The Jet DATESERIAL function returns a date given a year, month, and day
value. Transact-SQL does not have this function, but you can use DATEADD to
emulate it.
SSMA Access support: Yes
Solution: Replace DATESERIAL with expression as shown in the following example.
The year should be 4-digit only.
Example:
Jet
DateSerial(A, B, C)
SQL Server 2005
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Guide to Migrating from Microsoft Access to SQL Server 2005
45
DATEADD(day, Round(Cast(C as Integer) – 1, 0), DATEADD(month,
Round(Cast(B as Integer) - 1, 0), CAST(Str(Cast((A) as Integer)
+'0101') as datetime)))
Issue: The Jet HOUR function returns the hour of the day (a number from 0 to 23)
given a time value. Transact-SQL does not have this function, but you can use
DATEPART to emulate it.
SSMA Access support: Yes
Solution: Replace HOUR with DATEPART.
Example:
Jet
HOUR(NOW())
SQL Server 2005
DATEPART(hour, GETDATE())
Issue: The Jet MINUTE function returns the minute of the hour (a number from 0 to
59) given a time value. Transact-SQL does not have this function, but you can use
DATEPART to emulate it.
SSMA Access support: Yes
Solution: Replace MINUTE with DATEPART.
Example:
Jet
MINUTE(NOW())
SQL Server 2005
DATEPART(minute, GETDATE())
Issue: The Jet MONTHNAME function returns a string representing the month given
a number from 1 to 12. Transact-SQL does not have this function, but you can
emulate it by using DATENAME.
SSMA Access support: Yes
Solution: Replace MONTHNAME with DATENAME.
Example:
Jet
MONTHNAME(MonthNumber)
SQL Server 2005
DATENAME(month, cast('1900' + Right('0' + (LTrim(Str(MonthNumber))), 2)
+ '01' as datetime))
Issue: The Jet SECOND function returns the second of the minute (a number from 0
to 59) given a time value. Transact-SQL does not have this function, but you can
emulate it by using DATEPART.
SSMA Access support: Yes
Solution: Replace SECOND with DATEPART.
Example:
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Guide to Migrating from Microsoft Access to SQL Server 2005
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Jet
SECOND (NOW())
SQL Server 2005
DATEPART(second, GETDATE())
Issue: Jet has a DATE function that returns the date only. Transact-SQL does not
have such a function.
SSMA Access support: Yes
Solution: Replace DATE with an expression as shown in the following example.
Example:
Jet
DATE()
SQL Server 2005
CONVERT(datetime,CONVERT(varchar,GETDATE(),1))
Issue: Jet has a DATEVALUE function. Transact-SQL does not have such a function.
SSMA Access support: No
Solution: Write a UDF to emulate this function.
Example:
Jet
DATEVALUE("Jun 30")
SQL Server 2005
No equivalent
Issue: The Jet TIME function returns the time only. Transact-SQL does not have
such a function.
SSMA Access support: No
Solution: Use the following expression:
select convert(datetime, '12/30/1899 ' + convert(varchar,getdate(),14))
to emulate this function
Issue:
The Jet TIMESERIAL function returns time only. Transact-SQL does not have such a
function.
SSMA Access support: No
Solution: Write a UDF to emulate TIMESERIAL. The datetime value should have
the date set as 12/30/1899.
Example:
Jet
TIMESERIAL(hoursexpression, minuteexpression, secondexpression)
SQL Server 2005
No equivalent
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Issue: The Jet TIMEVALUE function returns the time only. Transact-SQL does not
have such a function.
SSMA Access support: No
Solution: Write UDF to emulate TIMEVALUE. The datetime value should have date
set as 12/30/1899.
Example:
Jet
TIMEVALUE("3:12:54 PM")
SQL Server 2005
No equivalent
Issue: The Jet WEEKDAY function returns a number representing the day of the
week (a number from 1 to 7) given a date value. Transact-SQL does not have this
function, but you can use DATEPART to emulate it.
SSMA Access support: Yes (partial)
Solution: Replace WEEKDAY with DATEPART if you do no have an optional
parameter defined, or create a UDF with the same name to emulate full
functionality.
Format 1:
Jet
WEEKDAY(NOW())
SQL Server 2005
DATEPART(weekday, GETDATE())
Format 2:
Jet
WEEKDAY(NOW(), firstdayofweek)
SQL Server 2005
No equivalent (emulated as UDF)
Issue: The Jet WEEKDAYNAME function returns a string representing the day of the
week given a number from 1 to 7. Transact-SQL does not have such a function.
SSMA Access support: No
Solution: Write a UDF to emulate this function.
Example:
Jet
WEEKDAYNAME (Number [, abbreviate [, firstdayiofweek]])
SQL Server 2005
No equivalent (emulated as UDF)
Issue: Jet has the DateAddW function (wrote on Basic) that adds work days to a
date. Transact-SQL does not have a similar function.
SSMA Access support: No
Solution: Write a UDF to emulate DateAddW.
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Guide to Migrating from Microsoft Access to SQL Server 2005
48
Example:
Jet
DATEADDW (Date, days)
SQL Server 2005
No equivalent (emulated as UDF)
Data Type Conversion Functions
You can convert most data type conversion functions as CAST functions, as the
following table shows. Note that if you convert into integer types, the values should
be rounded.
Jet SQL
Transact-SQL
CByte(expression)
CAST (ROUND(expression, 0) as tinyint)
CCur(expression)
CAST (expression as money)
CDate(expression)
CAST (expression as datetime)
CDbl(expression)
CAST (expression asfloat)
CDec(expression)
CAST (expression as decimal)
CInt(expression)
CAST (ROUND(expression, 0) as
smallint)
CLng(expression)
CAST (ROUND(expression, 0) as integer)
CSng(expression)
CAST (expression as real)
CStr(expression)
CAST (expression as varchar)
CVar(expression)
CAST (expression as sql_variant)
CVDate(expression)*
CAST (CAST (expression as datetime) as
sql_variant)
* This is an old variant of the CDate() function. It converts an expression into the
datetime type but returns it as a variant type.
SSMA Access support: Yes (partialy)
SQL Server 2005 does not have a Boolean type, therefore you cannot convert
function CBool without analyzing the code where it is used.
Aggregate Functions
You can move most aggregate functions (Avg(), Count(), Min(), Max(), Sum())
without any modification.
Issue: The Jet AVG function returns the average (arithmetic mean) of a set of
numeric values in a select query. Transact-SQL has a function with the same name
and similar functionality.
SSMA Access support: Yes
Solution: No changes required.
Example:
Jet
AVG(expression)
SQL Server 2005
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Guide to Migrating from Microsoft Access to SQL Server 2005
49
AVG(expression)
Issue: The Jet COUNT function returns the number of records in a select query.
Transact-SQL has a function with the same name and similar functionality.
SSMA Access support: Yes
Solution: No changes required.
Example:
Jet
COUNT(expression)
SQL Server 2005
COUNT(expression)
Issue: The Jet MIN function returns the minimum value in a set of numeric values
in a select query. Transact-SQL has a function with the same name and similar
functionality.
SSMA Access support: Yes
Solution: No changes required.
Example:
Jet
MIN(expression)
SQL Server 2005
MIN(expression)
Issue: The Jet MAX function returns the maximum value in a set of numeric values
in a select query. Transact-SQL has a function with the same name and similar
functionality.
SSMA Access support: Yes
Solution: No changes required.
Example:
Jet
MAX(expression)
SQL Server 2005
MAX(expression)
Issue: The Jet SUM function returns the sum of a set of numeric values in a select
query. Transact-SQL has a function with the same name and similar functionality.
SSMA Access support: Yes
Solution: No changes required.
Example:
Jet
SUM(expression)
SQL Server 2005
SUM(expression)
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Issue: The Jet FIRST function returns the first value that was inserted into a table
from the result set of a query. Transact-SQL does not have such a function.
SSMA Access support: No
Solution: In this situation, many conditions must be emulated. Note that there is no
guarantee that the order of unsorted records in Transact-SQL will be the same as in
the original table; therefore, the first element may be different. You can use a Top 1
subquery to extract the first value. (If you have one First() function as a field, there
is no need to use a subquery.) If the SELECT statement has conditions, duplicate
them in the subquery as well. The Jet FIRST function can be emulated only when the
source statement does not include the GROUP BY clause. It is possible that this
emulation will work differently after data migration if the table has one or more
indexes.
Example 1:
Jet
SELECT FIRST(expression), <other_aggregate_functions> from
SomeTable
SQL Server 2005
SELECT (SELECT Top 1 expression From SomeTable) as first,
<other_aggregate_functions> From SomeTable
Example 2:
Jet
SELECT FIRST(expression) from SomeTable
SQL Server 2005
SELECT Top 1 expression From SomeTable
Issue: The Jet LAST function returns the last value that was inserted into a table
from the result set of a query. Transact-SQL does not have such a function.
SSMA Access support: No
Solution: In this situation, many conditions must be emulated. Note that there is no
guarantee that the order of unsorted records in Transact-SQL will be the same as in
the original table; therefore, the last element may be different. You can use a Top 1
subquery to retrieve last value, but the same functionality can be emulated only if
the last inserted record can be found. This is often an identity field.
If there is one Last() function as a field, the subquery is unnecessary. If the SELECT
statement has conditions, these should be duplicated in the subquery as well. This
function can be emulated only when the source statement does not have a GROUP
BY clause.
Example:
Jet
SELECT LAST(expression), <other_aggregate_functions> From
SomeTable
SQL Server 2005
SELECT (SELECT Top 1 expression From SomeTable Order by
IdentityField Desc) as first, <other_aggregate_functions>
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From SomeTable
Example 2:
Jet
SELECT LAST(expression) From SomeTable
SQL Server 2005
SELECT Top 1 expression From SomeTable Order by IdentityField
Desc
Data Migration
This section covers aspects of the data migration that is performed by SSMA Access.
Generally, data is transferred without any transformation from the Jet store into the
SQL Server 2005 database during data migration. The connection is established
from SSMA Access to Access/Jet and to SQL Server 2005. Since you cannot assume
that SQL Server 2005 can connect back to the .mdb file, solutions that are based on
linked servers are not applicable.
Data Transfer Source
SSMA Access moves the data from the source table to the destination table.
Currently, moving data from an Access/Jet linked table to SQL Server 2005 is not
supported. If you have already linked the table and want to retransfer the data, you
must unlink the table by using the SSMA Access command before you can transfer
the data. It is possible that in the future the moving of data from a linked table will
be supported.
Data Transformation
SSMA Access does not change the transfer data and relies on the implicit data
conversion done by ADO.NET. The only exception is the date range. Date values that
are earlier than the SQL Server 2005 limit—1 Jan 1753—are converted to
1 Jan 1753 and a warning is generated. SSMA Access reads each date column value
and checks that the value is not before 1 Jan 1753. If it is, SSMA Access uploads to
the server the date 1 Jan 1753 instead of the underlying value.
Technology Used for the Data Migration
During development, after much evaluation of various technologies such SSIS and a
linked table data pump (insert into linked_table from select * from
source_table), it was decided that the SQL Server Migration Assistant would use
the OleDbConnection class to read the source and
System.Data.SqlClient.SqlBulkCopy to write to the destination (bulk copy write).
This proved to be reliable, simple, and highly performing.
Transaction Boundaries
There are no functional requirements on transaction boundaries when uploading
data to SQL Server 2005. SSMA Access groups multiple rows in a single transaction
for better performance; it is up to the in-house development team to find the correct
number of rows for each transaction. Our initial finding yields that 1,000 rows in a
single transaction is a good starting point.
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Guide to Migrating from Microsoft Access to SQL Server 2005
52
Conclusion
You now know the algorithms that SSMA Access uses to perform conversions and
can better understand the processes that are executed when the SSMA Access
Migration Wizard upsizes a database. For those rare cases when SSMA Access does
not handle a particular migration issue, you have approaches to manual conversion.
If you need help on SSMA Access or have a question about migrating from Access to
SQL Server 2005, send us an e-mail at acc2sql@microsoft.com.
For more information:
http://www.microsoft.com/sql/solutions/migration/default.mspx
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