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 such as the following:
The ODBC driver installation program installs a default version of the odbcinst.ini file in the product installation directory. 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 may include a section 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. If the information in these two sections is not the same, the values in the odbc.ini[ODBC] section override those of the odbcinst.ini[ODBC] section.
