Symfony/Doctrine: access to the join tables? - doctrine-orm

Question

In order to circumvent a problem I had with variations of entities the dirty way, I'm trying to constrain the number of colours available for a device repair. The available colours must not exceed the colours available for the device.
So I have:
Device.php
This maps the device to the colours and the repairs available for this device.
/**
* #ORM\OneToMany(targetEntity="Repair", mappedBy="device", cascade={"remove"})
*/
private $repairs;
/**
* #ORM\ManyToMany(targetEntity="Color", inversedBy="devices")
* #ORM\JoinTable(name="devices_colors",
* joinColumns={#ORM\JoinColumn(name="device_id", referencedColumnName="id")},
* inverseJoinColumns={#ORM\JoinColumn(name="color_id", referencedColumnName="id")}
* )
*/
private $colors;
Color.php
/**
* #ORM\ManyToMany(targetEntity="Device", mappedBy="colors")
*/
private $devices;
Repair.php
This maps a repair job to a device but also to a colour.
/**
* #ORM\ManyToOne(targetEntity="Device", inversedBy="repairs")
* #ORM\JoinColumn(name="device_id", referencedColumnName="id")
*/
private $device;
/**
* #ORM\ManyToMany(targetEntity="Color")
* #ORM\JoinTable(name="repairs_colors",
* joinColumns={#ORM\JoinColumn(name="repair_id", referencedColumnName="id")},
* inverseJoinColumns={#ORM\JoinColumn(name="color_id", referencedColumnName="id")}
* )
*/
private $colors;
RepairType.php
Point here is to:
map this field 'colors' to the colours available in the Color Entity but limit these choices to what is available for this instance of Device
->add('colors', EntityType::class, array(
'label'=>'Kleuren',
'class'=>'AppBundle:Color',
'choice_label'=>'name',
'choice_value'=>'id',
'multiple'=>true,
'expanded'=>true,
'query_builder'=>function (EntityRepository $er) use ($device) {
return $er->createQueryBuilder('c')
->join('AppBundle:Device','d')
->where('d.id = :device')
->setParameter('device', $device);
}
)
)
Because I know that a devices_colors join table is created, I can achieve the desired result through the following MySQL query directly on the server:
SELECT c.name FROM colors c LEFT JOIN devices_colors d ON (d.color_id=c.id) WHERE d.device_id = 1
However, my attempts above in RepairType do not achieve the same results. I always get all the colours available, not just the ones that have been set on Device. What am I doing wrong?

Answer 1

I found a solution. First, I made the ManyToMany relationships (between Color and Repair, and between Color and Device) bidirectional by adding the properties devices and repairs to the Color entity.
Next, I wrote my query_builder attribute as such:
'query_builder'=>function (EntityRepository $er) use ($device) {
return $er->createQueryBuilder('c')
->join('c.devices','d','WITH','d = :device')
->setParameter('device', $device);
}
That ended up working fine-ish. But it feels like a dirty hack for the problem I had.