The ODBC Driver Manager

Data Source Names

A Data Source Name (DSN) is a named ODBC resource that specifies the location, driver type, and other parameters needed by an ODBC driver to access a database. The ODBC driver manager uses the information in the DSN to establish and manage the connection.

Figure 6.13 Three types of DSNs and their functions

There are three types of DSNs. Each type stores the information needed to connect to a database server, but they store it in different locations.

• User DSN Connection information is stored in the Windows registry of the computer on which the data connection is created.
• System DSNs are local to a computer, rather than dedicated to a user. The system, or any user having privileges, can use a data source set up with a system DSN.
• File DSN Connection information is stored in a file that can be read by any application, a feature that makes a project more easily portable between computers.