How to create this? You can create ODBC DSNs using a Windows Control Panel. See Control Panel->Administrative Tools->Data Sources (ODBC). There are tabs for various types of DSNs. Select the one you need. If you run this control panel item on a 64bit OS, then by default it creates a 64bit ODBC DSN.
What is the main use of it? Not sure I understand what you mean. ODBC DSNs are created in the Windows System, not in the application. So they are essentially local to your platform and don't travel with your applications. System DSNs are available to all applications from all users, User DSNs are only available to applications run by that same user. OLE DB on the other hand doesn't use DSNs or Windows definitions to create database connections, just driver software and a connection specification in the application itself. So you may ask yourself whether ODBC is worth the effort.
How to create this? You can create ODBC DSNs using a Windows Control Panel. See Control Panel->Administrative Tools->Data Sources (ODBC). There are tabs for various types of DSNs. Select the one you need. If you run this control panel item on a 64bit OS, then by default it creates a 64bit ODBC DSN.
What is the main use of it? Not sure I understand what you mean. ODBC DSNs are created in the Windows System, not in the application. So they are essentially local to your platform and don't travel with your applications. System DSNs are available to all applications from all users, User DSNs are only available to applications run by that same user. OLE DB on the other hand doesn't use DSNs or Windows definitions to create database connections, just driver software and a connection specification in the application itself. So you may ask yourself whether ODBC is worth the effort.
