Called to get the default connection string.
The framework calls this member function to get the default connection string for the data source on which the recordset is based. ClassWizard implements this function for you by identifying the same data source you use in ClassWizard to get information about tables and columns. You will probably find it convenient to rely on this default connection while developing your application. But the default connection may not be appropriate for users of your application. If that is the case, you should reimplement this function, discarding ClassWizard's version. For more information about connection strings, see the article Data Source (ODBC).