多对多关系在laravel中返回null

Question

表user 和clinic 之间存在多对多关系，第三个表是user_clinics。所有三个表都完美地单独返回它们的值，但是当我调用 App\User::find(1)->clinics 或其逆时它返回 null。此外，user_clinic 具有 user_id 和 clinic_id 以及 previlage_id 作为外键。

public function users() {
    return $this->belongsToMany(User::class,'user_clinics','user_id','clinic_id');
}

public function clinics() {
   return $this->belongsToMany(Clinic::class,'user_clinics','clinic_id','user_id');
}

public function adminDashboard(Request $request) {
    $clinic = new Clinic();
    $User_clinic = new User_clinic();
    $user = new User();

    $clinic->name = $request->name;
    $clinic->address = $request->address;

    if($request->hasFile('logo')) {
        $fileName = $request->logo->getClientOriginalName();
        $request->logo->storeAs('public/logos',$fileName);
        $clinic->logo = $request->logo;
    }

    $clinic->save();

    $User_clinic->user_id = auth::user()->id;
    $test=$User_clinic->clinic_id = $clinic->id;

    //now hardcoded previlage_id but deal with it in future...
    $User_clinic->previlage_id = 1;
    $User_clinic->save();

    $test= $clinic::find(2)->users;

    dd($test);

     //return view("admin.dashboard.dashboardFirstPage");
} 

Answer 1

你们的关系不平静吧：

public function users() {
 return $this->belongsToMany(User::class,'user_clinics','user_id','clinic_id');
}

public function clinics() {
 return $this->belongsToMany(Clinic::class,'user_clinics','clinic_id','user_id');
}

应该是这样的：

在用户模型中：

public function clinics() {
 return $this->belongsToMany(Clinic::class,'user_clinics','user_id','clinic_id');
}

在临床模型中：

public function users() {
 return $this->belongsToMany(User::class,'user_clinics','clinic_id','user_id');
}