Doctrine 2 DQL - Select rows where a many-to-many field is empty?

Question

I have two classes in this example - DeliveryMethod and Country. They have a many-to-many relationship with each other.

What I want to do is select all DeliveryMetho

Answer 1

Can't join NULL values, IIRC. Apologies for the typo on twitter, should have said "can't".