调用未定义的方法Illuminate \\ Database \\ Eloquent \\ Collection :: save（）laravel

Question

I made a function that brings me to the error:

Call to undefined method Illuminate\\Database\\Eloquent\\Collection::save()

I can't understand why it is throwing

public function multiplelinkPlayerWithFamily($parent_id)
{
    $player_id = Input::get('player_id');
    $CheckRelationship = UsersRelationship::where('parent_user_id', $parent_id)->where('child_user_id', $player_id)->first();

    if($CheckRelationship) {
        return Response::json( [
            'ok'=> false,
            'message'=> 'The profiles are currently linked '
        ] ,422);
    }

    $user = User::find($player_id);

    $user->parent_id = $parent_id;
    $user->updated_by = $parent_id;

    $user->save();

    $UsersRelationship = new UsersRelationship;

    $UsersRelationship->parent_user_id = $parent_id;
    $UsersRelationship->child_user_id = $player_id;

    $UsersRelationship->save();

    $udata = ApiUserController::getLoginUserData();

    return Response::json([
        'ok'=> true,
        'message'=> 'Linked',
        'udata'=> $udata
    ] ,200);
}

Answer 1

I can't see how your models are structured, but it looks like you've actually turned a model into a relation: ie. $UsersRelationship It looks like you're trying to set up a many-to-many relation between users, correct?

public function parents()
{
    return $this->belongsToMany('User','users_relationships','child_id','parent_id');
}

 public function children()
 {
    return $this->belongsToMany('User','users_relationships','parent_id','child_id');
 }

Once you've got the relations set up right, you can call:

$user->parents()->attach($parent_id);

Answer 2

All multi-result sets returned by Eloquent, either via the get method or a relationship, will return a collection object. If the result of your query is likely to return more than one value, Laravel returns a collection. Understanding query methods that returns a Collection would save you the problem of calling an Eloquent model method on a Collection.

Your query is most likely to return more than one record from the database or none from the database. This would cause 'Eloquent' to return a Collection even if the number of records found is One. Because the the returned value is a Collection, we would need to loop through the returned set to have access to the individual Model.

So try replace your below code:

$user = User::find($player_id);

$user->parent_id = $parent_id;
$user->updated_by = $parent_id;
$user->save();

and replace it as like given below:

$user = User::find($player_id);
$user->each(function($user)
{
    $user->parent_id = $parent_id;
    $user->updated_by = $parent_id;
    $user->save();
});

Hope it may work.