Doctrine 2 is an object-relational mapper (ORM) for PHP 7.1+ that provides transparent persistence
for PHP objects. It sits on top of a powerful database abstraction layer (DBAL). One of its key features
is the option to write database queries in a proprietary object oriented SQL dialect called Doctrine Query Language (DQL),
inspired by Hibernate's HQL. This provides developers with a powerful alternative to SQL that maintains flexibility
without requiring unnecessary code duplication.
More resources: