调用未定义的方法Illuminate \ Database \ Query \ Builder :: getMorphClass（）

Question

DB structure:

items ( id, ... )
photos ( id, ... )
comments ( id, entity_id, entity_type )

where entity_type is an ENUM ('Item', 'Photo')

Models:

class Item extends Eloquent {
  public function comments() {
    return $this->morphMany('Comment', 'entity');
  }
}
class Photo extends Eloquent {
  // same as Item
}
class Comment extends Eloquent {
  public function entity() {
    return $this->morphTo();
  }
}

For some reason when I try this:

$comments = $item->comments()->orderBy('created_at', 'asc')->get();

I get this error.

Call to undefined method Illuminate\Database\Query\Builder::getMorphClass()

It seems like it's trying to use the Query Builder instead of MorphOneOrMany, which does have getMorphClass defined. But even if I simply do $item->comments without any further query building, it gives the same error.

Answer 1

Here is my temporary solution

class Item extends Eloquent {
  public function comments() {
    return $this->hasMany('Comment', 'entity_id')
      ->where('entity_type', '=', 'Item');
  }
}

I would really prefer to use morphMany though.