Doctrine2: Polymorphic Queries: Searching on properties of subclasses

Here's another solution that works for me with Doctrine 2.4:

$qb->select('o')
   ->from('Order', 'o')
   ->leftJoin('AmazonOrder', 'ao', 'WITH', 'o.id = ao.id')
   ->andWhere('o.id like :query or ao.amazonOrderId like :query')
   ->setParameter('query', $someQuery);

You just left-join the entity on the specific subclass of itself. (You can adapt my simple query to your use case.)

I've tried this exactly once, but it seems to work.

Hm, I had similiar problems in my last doctrine project.

One time it was just a single field, so I moved it to the parent class – not the nicest solution, but worked. In some other case there where too many properties so these would have cluttered the parent class. I did a native sql query for searching and fetching me the record ids and then used a WHERE IN (...) dql in order to fetch the entities.

A compromise might be the doctrine ResultSetMapping which can map a native sql query to entities directly, although every time I worked with it I found it quite clumsy to use and the overhead for two queries (fetch ids & fetch entites) as outlined above to be neglectable.

Maybe you could accomplish something with the INSTANCEOF operator in your WHERE clause, although I dont think doctrine would be smart enough to recognize it the way you want.