Php 无法删除一对多关系中的记录

我对laravel中的以下错误感到震惊： 有两个具有多对多关系的表用户和磁道，中间表名为track\u user我正在尝试删除记录，但无法删除

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`)) 

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

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

用户型号：

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`)) 

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

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

---

您必须首先从复合用户跟踪表中删除该记录。只有这样，才能删除跟踪表中的父记录

您必须首先从复合用户跟踪表中删除该记录。只有这样，才能删除跟踪表中的父记录

来自laravel文档的“附加的反面是分离：”

在地图上找

离开的例子：

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

在laravel文档中，“附加的反面是分离：”

在地图上找

离开的例子：

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

---

如何删除复合表中的记录？如何删除复合表中的记录？