Warning: You are browsing the documentation for Symfony 4.2, which is no longer maintained.
Read the updated version of this page for Symfony 5.3 (the current stable version).
Doctrine2 is very flexible, and the community has already created a series of useful Doctrine extensions to help you with common entity-related tasks.
The usage for each of these extensions is explained in that repository.
However, to install/activate each extension you must register and activate an Event Listener. To do this, you have two options: