Laravel 多态有一个，两个不同的类别 model 到同一个项目

Question

I'm trying to use two different Category model to the same items table.

I'v got 3 models

SystemCategory

Schema::create('system_categories', function (Blueprint $table) {
        $table->bigIncrements('id');
        $table->string('name');
        $table->timestamps();
    });

UserCategory

Schema::create('user_categories', function (Blueprint $table) {
        $table->bigIncrements('id');
        $table->string('name');
        $table->integer('user_id');
        $table->timestamps();
    });

Item

Schema::create('items', function (Blueprint $table) {
        $table->bigIncrements('id');
        $table->string('name');
        $table->integer('categoryable_id');
        $table->string('categoryable_type');
        $table->timestamps();
    });

Item category could be either from system_categories or user_categories table

I saw some Polymorphic relations but its about how two different models can belongs to one category, not about how model can belongs to two different category models

Thanks.

Answer 1

It can be done, first thing your schema looks ok but you want to set catagoryable_id to a bigInteger to match the id columns of the 2 category tables.

Then you would set your models up

class Item extends Model
{
    public function categoryable() 
    {
        return $this->morphTo();
    }
}

class SystemCategory extends Model
{
    public function items()
    {
        return $this->morphMany('App\Item', 'categoryable');
    }
}

class UserCategory extends Model
{
    public function items()
    {
        return $this->morphMany('App\Item', 'categoryable');
    }
}

Obviously this is presuming your models are in the App namespace