问题
Okay, so I'm trying to create a relationship where users can follow other users or follow categories. I got a recommendation to use Polomorpic Many to Many relationships. Right now I'm trying to create a follower - followee relationship but I can't wrap my head around how to set up the models and the controller.
TABLES
Users
Schema::create('users', function (Blueprint $table) {
$table->increments('id');
$table->string('email');
$table->string('password');
$table->string('first_name');
});
Categories
Schema::create('categories', function (Blueprint $table) {
$table->increments('id');
$table->string('category');
});
Followables
Schema::create('followables', function (Blueprint $table) {
$table->increments('id');
$table->timestamps();
$table->integer('user_id');
$table->integer('followable_id');
$table->string('followable_type');
});
MODELS
User
class User extends Model implements Authenticatable
{
public function followers()
{
return $this->morphToMany('App\Followable', 'followable');
}
public function following()
{
return $this->morphedByMany('App\Followable', 'followable');
}
//Use to get id from Auth facade
public function getId()
{
return $this->id;
}
}
Followable
class Followable extends Model
{
protected $fillable = ['user_id'];
public function followable()
{
return $this->morphTo();
}
}
The Category model follower relationship does not exist yet so I will leave that one out for now.
CONTROLLER
FollowableController
class FollowableController extends Controller
{
public function followUser($followable_id){
$user_id = Auth::user()->getId();
$followee = User::find($followable_id);
$followee->followers()->create(['user_id' => $user_id]);
return redirect()->route('get.user', ['user_id' => $followable_id]);
}
}
To be honest I'm a bit confused by the code I've created. It's been some copy and pasting without understanding 100 % of what I do. Anyways, this will create two records in the database looking like this:
Followable
-------------------------------------------------
|Id | user_id | followable_id | followable_type |
-------------------------------------------------
|22 | 4 | NULL | NULL |
-------------------------------------------------
|23 | 0 | 22 | App\User |
-------------------------------------------------
The followable_id is wrong and seems to use the Id which is created in the Followable table instead of the user_id from the User table.
So, how to solve so that there is only one record being saved to the database with the right followable_id?
回答1:
I guess you are using the wrong method. I did something like that following Laravel's doc example, and morphMany() was sufficient, since your User can have many followers, which are themselves user so you can have:
User model:
public function followers()
{
return $this->morphMany('App\Followable', 'followable');
}
Then you can set the user_id from the controller (but don't forget to add it to fillable).
Hope it helps :)
来源：https://stackoverflow.com/questions/42205928/how-to-create-follower-relationships-using-polymorphic-many-to-many-relationship