What are some OOP strategies for working with a database but keeping thing testable? Say I have a User class and my production environment works against MySQL. I see a couple possible approaches, shown here using PHP:

1. Pass in a $data_source with interfaces for load() and save(), to abstract the backend source of data. When testing, pass a different data store.

    $user = new User( $mysql_data_source ); $user->load( 'bob' ); $user->setNickname( 'Robby' ); $user->save(); 

2. Use a factory that accesses the database and passes the result row to User's constructor. When testing, manually generate the $row parameter, or mock the object in UserFactory::$data_source. (How might I save changes to the record?)

    class UserFactory { static $data_source; public static function fetch( $username ) { $row = self::$data_source->get( [params] ); $user = new User( $row ); return $user; } } 

I have Design Patterns and Clean Code here next to me, but I'm struggling to find applicable concepts.

What are some OOP strategies for working with a database but keeping things unit testable? Say I have a User class and my production environment works against MySQL. I see a couple possible approaches, shown here using PHP:

1. Pass in a $data_source with interfaces for load() and save(), to abstract the backend source of data. When testing, pass a different data store.

    $user = new User( $mysql_data_source ); $user->load( 'bob' ); $user->setNickname( 'Robby' ); $user->save(); 

2. Use a factory that accesses the database and passes the result row to User's constructor. When testing, manually generate the $row parameter, or mock the object in UserFactory::$data_source. (How might I save changes to the record?)

    class UserFactory { static $data_source; public static function fetch( $username ) { $row = self::$data_source->get( [params] ); $user = new User( $row ); return $user; } } 

I have Design Patterns and Clean Code here next to me, but I'm struggling to find applicable concepts.