In theory it should be so easy...running an APEX application on an Oracle instance with database links to MySQL for retrieving and modifying data. In theory that is, because in practice it is somewhat more cumbersome. I finally got there, but it took some steps - and patience... I started off with the steps provided from a couple of websites. Like these from Birijan , from Pythian , from WebAJ and from Easysoft . They´re all not the most recent ones, so I downloaded the latest versions of MySQL (5.1.51), MySQL Connector for ODBC (5.1.7) and unixODBC (2.3.0) and installed this stuff on top of the Oracle Developer Days Virtual Machine. Following the steps provided on the sites earlier mentioned I had a MySQL database with a demo table within minutes. So far so good! After changing the odbcinst.ini, odbc.ini, tlistener.ora, tnsnames.ora and the initmysql.ora (in $ORACLE_HOME/hs/admin) file I fired up SQL*Plus and created a databaselink using create database link mysql ...