尝试使用 doctrine 查询生成器的 select 左连接为 null

Question

I'm trying to select all Rooms that are not occupied on given Reservation dates.
I've created such code:

$queryBuilder->select('rm')
            ->from('App:Room', 'rm')
            ->leftJoin('App:Reservation', 'r', 'WITH', $queryBuilder->expr()->andX(
                $queryBuilder->expr()->lt('r.start', '?1'),
                $queryBuilder->expr()->gt('r.stop', '?2'),
                $queryBuilder->expr()->neq('r.status', '?3')
                )
            )->where(
                $queryBuilder->expr()->andX(
                    $queryBuilder->expr()->isNull('r')
                )
            )->setParameters(
                array(
                    1 => $stop,
                    2 => $start,
                    3 => Reservation::STATUS_EXPIRED
                )
            ); 

I have 2 reservations on 2 rooms, where room id equals reservation id:

1. 2000-01-01 - 2000-01-02
2. 2000-01-01 - 2000-01-03

Also $start = '2000-01-02' and $stop = '2000-01-05' and status of both reservations is Reservation::STATUS_NEW
I would expect that given these dates, this query would return me room 1., as room 2 has reservation colliding with them but the result is empty.
Removing the where clause results in both rooms being returned. In this case $queryBuilder->getQuery()->getArrayResult() returns both rooms and reservation number 2. as expected, but when I restore the where clause, the array is just empty.

My another approach is through a subquery but it behaves exactly the same so please advise, what am I missing?

$queryBuilder = $this->getEntityManager()->createQueryBuilder();
        $all = $this->getEntityManager()->createQueryBuilder();

        $all->select('rma.id')
            ->from('App:Room', 'rma')
            ->innerJoin('App:Reservation', 'r')
            ->where(
                $all->expr()->andX(
                    $all->expr()->lt('r.start', '?1'),
                    $all->expr()->gt('r.stop', '?2'),
                    $all->expr()->neq('r.status', '?3')
                )
            );

        $queryBuilder->select('rm')
            ->from('App:Room', 'rm')
            ->where(
                $queryBuilder->expr()->neq(
                    'rm.id',
                    $queryBuilder->expr()->all(
                        $all->getDQL()
                    )
                )
            )->setParameters(
                array(
                    1 => $stop,
                    2 => $start,
                    3 => Reservation::STATUS_EXPIRED
                )
            );

Answer 1

you would want to exclude rooms, where the reservations have overlap with the query date span.

that is

$queryBuilder->expr()->lt('r.start', '?1'), // 1 being stop
$queryBuilder->expr()->gt('r.stop', '?2'),  // 2 being start

which you already had correct. however, your null check is off, it should be:

$queryBuilder->expr()->isNull('r') // <-- you had rm here

so, r is obviously the reservation, and that one should be null ("missing").

(I always find that using short aliases makes it really really hard to spot those kinds of errors, and it's so little actual time saved..., I also much prefer named parameters over numbered parameters)

update

Okay, I missed the main point being wrong here;o/

your query matches all rooms with all reservations (not just the reservations of that room), and selects those, that "have" no reservation. Meaning: if there is a reservation for the date span, you get back NO rooms, and if there is no reservation for the date span, you get back ALL rooms.

There's two ways to make the querybuilder do the right thing, which depends on your mapping definition, but I will assume, that the Room entity has a field reservations that holds all reservations for that room.

$qb->from('Room', 'rm')
   ->leftJoin('rm.reservations', 'r', 'WITH', ...)

The difference being, that the "table" descriptor implies that the reservations are of the respective room and only joined with those.

Or being explicit:

$qb->from('Room', 'rm')
   ->leftJoin('Reservation', 'r', 'WITH', $qb->expr()->andX('r.room=rm', ...))

That should finally solve your problem.

Answer 2

The answer above placed me on the right track to understand my failure.
My final code looks like this:

$queryBuilder->select('rm')
            ->from('App:Room', 'rm')
            ->leftJoin('rm.reservations', 'r', 'WITH', $queryBuilder->expr()->andX(
                $queryBuilder->expr()->lt('r.start', '?1'),
                $queryBuilder->expr()->gt('r.stop', '?2'),
                $queryBuilder->expr()->neq('r.status', '?3')
                )
            )->where(
                $queryBuilder->expr()->andX(
                    $queryBuilder->expr()->isNull('r')
                )
            )->setParameters(
                array(
                    1 => $stop,
                    2 => $start,
                    3 => Reservation::STATUS_EXPIRED
                )
            );

It was all about joining rm.reservations , not general App:Reservation as I did. Assocations are well defined inside Entity classes and Doctrine will add proper constraints if I point to field of the object instead of general class.
Example given by Jakumi would work ok for a ManyToOne assocation, in my case (ManyToMany) I would have to manually join the joining table between Reservation and Room.