Question

Is it possible in DQL, to specify the class name as a WHERE or GROUP BY clause?

That would be very useful when having a hierarchy of users, for example:

SELECT a FROM Article a
JOIN a.owner o
WHERE o.class = ?

SELECT u.class, COUNT(*)
FROM User u
GROUP BY u.class

Answer 1

There’s the “INSTANCE OF” syntax in DQL:

your first example:

SELECT a FROM Article a
JOIN a.owner o
WHERE o INSTANCE OF 'Editor'

I’m not sure you do what you’re trying to do in the second case, though.