DataLink database parameter
Description
Specifies that you want to create a file or use an existing
file containing your connection information to connect to your data
source.
When to specify DataLink
You must specify the DataLink parameter before connecting
to the database.
Controls
-
ADO.NET
-
OLE DB
-
SNC SQL Native Client for Microsoft SQL Server
Syntax
|
1 |
DataLink='<span>file_name</span>' |
Default
None
Usage
The Data Link option allows you to access Microsoft’s
Data Link API. The Data Link API allows you to define a file or
use an existing file that contains your connection information.
A Data Link file is identified with the suffix .udl.
To launch the API, double-click on Manage Data Links under
OLE DB Utilities in the Installed Database Interfaces list or select
the File Name check box on the Connection page in the Database Profile
Setup dialog box and click the button next to the File Name box.
For more information on using the Data Link
API, see Microsoft’s Universal Data Access Web site.
Using a Data Link file versus setting other database
parameters
If you use a Data Link file to connect to your data source
with the ADO.NET or OLE DB interface, all other settings you make
in the Database Profile Setup dialog box are ignored.
If you use a Data Link file to connect to your data source
with the SNC interface, the setting
in the ProviderString database parameter still takes effect. The SNC interface gets a connection string
from the data link file, and then copies the contents of the ProviderString
parameter into the connection string so that it contains the connection
parameters from both the data link file and the ProviderString parameter.
You might want to take advantage of this feature if you do not want
to save the user name and password in the UDL file. You can specify
them in the ProviderString parameter instead.
Examples
To use the file oledb.udl to
connect to an OLE DB data provider:
-
Database profile
Select the File Name check box on the Connection page in the
Database Profile Setup dialog box and enter a name for a new file
or select an existing file. -
Application
Type the following in code:
1SQLCA.DbParameter="DataLink='oledb.udl'"