Data Access and Transactions

Creating an ODBC-Compliant Data Source

When designing a Web database application, it is often easier to initially prototype with a desktop database like Access, and then scale up to an enterprise-level database like SQL Server once the design work has been finished. This is an easy alteration to make if you are using script, but it would require you to recompile your business object DLLs. With a connection string, you can make such a change without altering code in your application.

When you use an ODBC Data Source Name (DSN) entry to store the connection string values externally, you simplify the information needed in the connection string. This makes changes to the data source completely transparent to the code itself.

To create a new ODBC DSN

Click the Start menu button, point to Programs, then Administrative Tools.
Click the Data Sources (ODBC) icon, and select the System DSN tab.
Click Add to create a new DSN entry, and then select the appropriate OLE DB provider for your database from the list of installed providers. Click Finish to configure your provider.

Note Make sure you create either a File or System DSN. ADO does not recognize user (or local) DSNs. Because they store settings in the system registry, System DSNs offer slightly faster performance than File DSNs, which store connection parameters in a file on your hard disk.