ODBC drivers are specific to each type of database.
Where to Get an Oracle ODBC Driver
The Oracle ODBC Drivers Download Page is the source for official Oracle ODBC drivers.
The Easysoft ODBC Oracle Driver improves on the stock Oracle ODBC drivers by providing improved performance and easier maintenance.
OpenLink Software provides both Single-Tier and Multi-Tier Oracle ODBC drivers.
DataDirect Connect for ODBC is a replacement Oracle ODBC driver which provides improved performance and easier maintenance.
Attunity provides a data adapter which includes an Oracle ODBC driver.

Where to Get a MySQL ODBC Driver
MySQL Connector/ODBC is the official MySQL ODBC driver.
OpenLink Software provides both Single-Tier and Multi-Tier MySQL ODBC drivers.
Sources for Other ODBC Drivers
To search for an ODBC driver for another database, check Ken North’s extensive list of ODBC Drivers and Servers and the unixODBC list of ODBC drivers which work with unixODBC.
