1.4.14.1 MySQL

Warning: The MySQLdb module on which the MySQL driver is based automatically commits any changes you have made to the database when the script exits, regardless of whether you have explicitly committed the changes in the code. This is different to the behaviour of the other databases and may catch you out so please be aware it is going on. (If anyone knows how to fix this please, please let the authour know!)

Also, MySQL doesn't explicitly check the foreign key constraints and so won't let you know you try an operation which would break those constriants.