If you want your TYPO3 extensions to be DBAL compliant you might have to rewrite parts of them. The most basic DBAL support is to substitute all direct mysql\*() function calls with the wrapper functions found in DatabaseConnection accessed through the global object $GLOBALS['TYPO3_DB']. The most radical support is to consistently use the methods in the DatabaseConnection class prefixed exec_ - they will automatically create the proper SQL behind the scenes and execute the queries right away, returning a result pointer/object. This allows the DBAL to handle an ultimate amount of the interaction with the database for you.