inheritance - 2 mysql tables mapped as 1 extending entity -

I have the following setup:

• A principle unit client to host my principles
• A principle unit campaign client is mapped to my campaign_clients table

  , campaign_clients.client_id represents a foreign key for clients.id. In principle, you usually make a connection between those 2 objects.

  However, I have been told that Doctrine2 provides the ability to maintain a good OO structure for this: Class Campaign Client Export Client . In this way (according to the theory) I can retrieve the campaign client and receive $ campaign_client- & gt; GetClient (); All clients can make available fields without using .

  So my question is, what is it called? I've searched Google on many conditions but I do not know what to watch.

  I have been able to find something after searching more in the document. What do I need Class table inheritance: