Doctrine Project

[DDC-1553] JTI Joining root tables could include ON ... AND root.id IS NOT NULL for each root in the inheritance

Thu, 22 Dec 2011 11:21:52 +0000

Would lead to more optimal queries, while still allowing for LEFT JOIN. Also related to this:
https://groups.google.com/forum/#!topic/doctrine-user/znkkP7IF_Aw

[DDC-1552] JTI Owning table for identifier columns could/should be the entitytable

Thu, 22 Dec 2011 11:36:51 +0000

When ordering a JTI entity on id, the generated SQL will use the table of the root entity. This is because the root entity is listed as owner of the field in the _owningTableMap, leading to non-optimal queries.

More information see:
https://groups.google.com/forum/#!topic/doctrine-user/znkkP7IF_Aw

[DDC-1621] Add support for FROM Class1 a1 JOIN Class2 a2 WITH cond queries

Sun, 30 Dec 2012 20:16:47 +0000

Check feasibility of this kind of query different from FROM Class1 a1, Class2 a2 to allow arbitrary joins between classes.

[DDC-2235] Single table inheritance discriminator in WHERE when using arbitrary join syntax

Duplicate — Tue, 11 Jun 2013 00:56:23 +0000

The condition on the discriminator column is placed in the WHERE clause when using arbitrary join syntax, which renders LEFT JOINs useless.

Given these classes:
A - no inheritance
B1 - abstract, root of a hierarchy, discriminator column is named 'type'
I setup a query builder like this:

$qb->select('a.id AS idA, b.id AS idB')
    ->from('\Entity\A', 'a')
    ->leftJoin('\Entity\B1', 'b', \Doctrine\ORM\Query\Expr\Join::WITH, 'a.something=b.something');
And the SQL Doctrine generates is something like this:
SELECT a.id, b.id FROM a LEFT JOIN b ON (a.something=b.something) WHERE b.type IN ('1', '2', '3')

The problems is that the WHERE condition makes the left join useless.

The condition on the discriminator column should be placed in the JOIN clause to avoid the problem.