Microsoft Windows uses UDL (Universal Data Link) files
to point to specific data sources. The UDL file lists the location
of the data, the type of database, the version of the database,
and the appropriate database driver.
For each data source
that you use with AutoCAD Map 3D, you must have a UDL file in the AutoCAD Map 3D data
source directory. Once the UDL file exists in the data source directory,
you can attach the data source to any drawing.
For most data sources, AutoCAD Map 3D creates
the UDL file automatically when you attach a database. However,
for some database types, you must create the UDL file manually.
When you edit or create
a UDL file, you use the Microsoft Windows Data
Link Properties dialog box. For more information on using
this dialog box, refer to your Microsoft Windows documentation.
To read external data
files, AutoCAD Map 3D uses drivers that translate the data to a standard
format. The first time you use a data source with AutoCAD Map 3D, AutoCAD Map 3D determines
the appropriate driver for the data source. It stores this information
in the UDL file.
AutoCAD Map 3D supports these
- Jet provider, which works with Microsoft
Access database files
- SQL Server provider
- Oracle provider
- ODBC driver, which works with ODBC-compliant
These drivers are installed
with AutoCAD Map 3D.
Because the ODBC provider
works with many different database types, it requires additional
information about each specific database type. It gets this information
from a Data Source Name (DSN) that
registers information about the database type. You need only one
DSN for each database type.
For the following ODBC-compliant
databases, AutoCAD Map 3D creates a DSN for you when you attach the
- Microsoft Access
- Microsoft Excel
- Microsoft Visual FoxPro
By default, AutoCAD Map 3D connects
to Microsoft Access using the Jet provider, which does not require
a DSN. If you want to connect to Microsoft Access using the ODBC
driver, you must create a DSN.
For information on creating
a DSN, refer to your Microsoft Windows documentation.
When you attach a data
source that does not already have a UDL file, AutoCAD Map 3D creates
the UDL file and determines the settings for Windows data source
If the Expert variable
is set to 3 or more, AutoCAD Map 3D determines the settings, and displays
the data source configuration dialog boxes so you can review or
modify the settings.
you are using the ODBC provider, before you manually create the
data link file, you must have a DSN (Data Source Name)
for the database software. Windows may have created this file when
you installed your database software.