Connections to a data source can be made via a connection string without referring to a data source name (DSN-less connections). This is done by specifying the "DRIVER=" keyword instead of the "DSN=" keyword in a connection string, as outlined in the ODBC specification. A file named odbcinst.ini must exist when the driver encounters DRIVER= in a connection string.

Setup installs a default version of this file in the product installation directory (see "ODBCINST" for details about relocating and renaming this file). This is a plain text file that contains default DSN-less connection information. You should not normally need to edit this file. The content of this file is divided into several sections.

At the beginning of the file is a section named [ODBC Drivers] that lists installed drivers, for example,

This section also includes additional information for each driver.

The next section of the file is named [Administrator]. The keyword in this section, AdminHelpRootDirectory, is required for the Linux ODBC Administrator to locate its help system. The installation process automatically provides the correct value for this keyword.

The final section of the file is named [ODBC]. The [ODBC] section in the odbcinst.ini file fulfills the same purpose in DSN-less connections as the [ODBC] section in the odbc.ini file does for data source connections. See "Configuration Through the System Information (odbc.ini) File" for a description of the other keywords this section.