Can not execute has/whereHas on MorphTo relation.

[dkulyk]

• Laravel Version: 5.7.5
• PHP Version: 7.2.10
• Database Driver & Version: MySQL 10.2.17-MariaDB

Description:

Can not execute has/whereHas on MorphTo relation.
It throws RuntimeException('has() and whereHas() do not support MorphTo relationships.')
It happened after #25337

Steps To Reproduce:

Search all entities where exists $relatedEntity.

//Manually set entity type.
$builder->where('entity_type', $relatedEntity->getMorphClass());
$builder->getModel()->setAttribute('entity_type', $relatedEntity->getMorphClass());

$builder->whereHas('entity', function(Builder $builder) {
   //...
});

[staudenmeir]

As #25337 says, has() and whereHas() don't support MorphTo relationships.

#5429 and #18523 provide a detailed explanation and possible workarounds.

[laurencei]

Thanks @staudenmeir

[dkulyk]

They are support MotphTo relationships. But need specify a type, then it known what a table need to use.

if someone does not understand how MotphTo works, then the rest do not need to be deprived of the opportunity to use it.

[staudenmeir]

Revert to Laravel <5.6.35 and replace ->get() on your $builder query with ->toSql(). What's the result?

[dkulyk]

It worked in L5.5, after upgrading to 5.7 it doesn't work
L5.5:

>>> $q = \DtKt\Comments\Entities\Comment::query()
>>> $q->getModel()->entity_type = 'seminar_page';
>>> $q->where('entity_type','seminar_page')->whereHas('entity')
>>> $q->toSql()
=> "select * from `comments` where `entity_type` = ? and exists (select * from `seminars_pages` where `comments`.`entity_id` = `seminars_pages`.`id`) and `comments`.`deleted_at` is null"
>>> $q->getBindings()
=> [
     "seminar_page",
   ]

With different model for example L5.7 with disabled exception.

>>> $q = \DtKt\Comments\Entities\Comment::query()
>>> $q->getModel()->entity_type = \DtKt\Comments\Entities\Comment::class;
>>> $q->where('entity_type','seminar_page')->whereHas('entity')
>>> $q->toSql()
=> "select * from `comments` where `entity_type` = ? and exists (select * from `comments` as `laravel_reserved_0` where `laravel_reserved_0`.`id` = `comments`.`entity_id`) and `comments`.`deleted_at` is null"
>>> $q->getBindings()
=> [
     "seminar_page",
   ]

Example of production code: Search comments for entities.
$has is Closure like as Builder::has from L5.7 without exception.

foreach (Comments::all() as $name) {
    $builder->orWhere(function (Builder $builder) use ($has, $name, $search) {
        /* @var Model $entity */
        $entity = Comments::resolve($name);
        $builder->where('entity_type', $entity->getMorphClass());
        $builder->getModel()->setAttribute('entity_type', $entity->getMorphClass());
        $has->call($builder, 'entity', '>=', 1, 'and',
            function (Builder $builder) use ($search) {
                Nova::resourceForModel($builder->getModel())::applySearch($builder, $search);
            }
        ]);
    });
}

[staudenmeir]

How is the entity relationship defined?

[dkulyk]

HasMorphEntity.php

public function entity(): MorphTo
{
    return $this->morphTo('entity');
}

[staudenmeir]

Laravel 5.8.27 will add whereHasMorph(): #28928