Question

我对laravel中的以下错误感到震惊：有2个表用户和轨道有多对多关系，中间表名是track_user我试图删除记录但无法做到

Unhandled Exception

Message:

Call to a member function track() on a non-object
Location:

C:\wamp\www\integron\application\controllers\track.php on line 50

Mysql错误：

SQL query:
DELETE FROM  `integron`.`tracks` WHERE  `tracks`.`id` =2

MySQL said: 

#1451 - Cannot delete or update a parent row: a foreign key constraint fails (`integron`.`track_user`, CONSTRAINT `track_user_project_id_foreign` FOREIGN KEY (`track_id`) REFERENCES `tracks` (`id`))

用户模型：

<?php 
class User extends Eloquent{
public static $table = 'users';
public function tracks()
    {
        return $this->has_many_and_belongs_to('Track');
    }

跟踪模型：

<?php 
class Track extends Eloquent{
public static $table = 'tracks';
public function users()
    {
        return $this->has_many_and_belongs_to('User');
    }

控制器

//this funciton is working properly

public function post_trackUpdate($id){
    $track = Track::find($id);
    $track->name = Input::get('name');
    $track->description = Input::get('desc');
    $track->save();
}
//this funciton is not working properly
public function get_trackDelete($id){
    $track = Track::find($id);
    $track->delete();
}

...

//an alternate which i tried but didnt work either
public function get_trackDelete($id){
    $user=User::find($id);
    $user->tracks()->delete();
    Session::flash('result','track Details deleted');
    return Redirect::to('track');
}

Answer 1

从laravel docs＆＃34;附加的反面是分离：＆＃34;

在http://four.laravel.com/docs/eloquent

中查找

离开的例子：

$circle->users()->detach($user_id);
$circle->save();

Answer 2

您必须先从复合user_track表中删除该记录。只有这样才能删除轨道表中的父记录。

无法删除一对多关系laravel雄辩的记录

2 个答案: