Doctrine ORM for PHP - Defining ModelsAs we mentioned before, at the lowest level in Doctrine your schema is represented by a set of php classes that map the schema meta data for your database tables. In this chapter we will explain in detail how you can map your schema information using php code. One problem with database compatibility is that many databases differ in their behavior of how the result set of a query is returned. MySQL
http://www.doctrine-project.org/documentation/manual/1_2/en/dql-doctrine-query-language
