Question

I’d like to select order items from all orders with a specific item. In SQL I’d do it like this:

SELECT DISTINCT i.id, i.name, order.name 
FROM items i 
JOIN orders o ON i.order_id=o.id 
WHERE o.id IN (
   SELECT o2.id FROM orders o2
   JOIN items i2 ON i2.order_id=o2.id AND i2.id=5
)
AND i.id != 5
ORDER BY o.orderdate DESC
LIMIT 10

How would I do this query with the query builder?

Answer 1

This is how I would try it:

/** @var Doctrine\ORM\EntityManager $em */
$expr = $em->getExpressionBuilder();
$em->createQueryBuilder()
   ->select(array('DISTINCT i.id', 'i.name', 'o.name'))
   ->from('Item', 'i')
   ->join('i.order', 'o')
   ->where(
       $expr->in(
           'o.id',
           $em->createQueryBuilder()
               ->select('o2.id')
               ->from('Order', 'o2')
               ->join('Item', 
                      'i2', 
                      \Doctrine\ORM\Query\Expr\Join::WITH, 
                      $expr->andX(
                          $expr->eq('i2.order', 'o2'),
                          $expr->eq('i2.id', '?1')
                      )
               )
               ->getDQL()
       )
   )
   ->andWhere($expr->neq('i.id', '?2'))
   ->orderBy('o.orderdate', 'DESC')
   ->setParameter(1, 5)
   ->setParameter(2, 5)
   ;

I didn’t test this of course, and made some assumptions about your models. Possible problems:

• Limit: this has been somewhat of a problem in Doctrine 2, it seems query builder is not very good at accepting limits. Do take a look here, here and here.
• The IN clause is usually used with an array, but I think it will work with a subquery.
• You probably can use the same parameter ?1, instead of two parameters (because they’re the same value), but I’m not sure.

Concluding, this may not work first time, but will surely put you on the right track. Do tell us the final 100% correct answer afterwards.