Doctrine_Connection is a wrapper for database connection. It handles several things: * Handles database portability things missing from PDO (eg. LIMIT / OFFSET emulation) * Keeps track of Doctrine_Table objects * Keeps track of records * Keeps track of records that need to be updated / inserted / deleted * Handles transactions and transaction nesting * Handles the actual querying of the database in the case of INSERT / UPDATE / DELETE operations * Can query the database using the DQL API (see Doctrine_Query) * Optionally validates transactions using Doctrine_Validator and gives full information of possible errors.
