CODEWITHSUNDEEP
phplaraveleloquent
Daniel Euchar
Daniel Euchar

Reputation: 1820

unable to delete record in one to many relationship laravel eloquent

i am struck with the following error in the laravel: there are 2 tables users and tracks with many to many relationship and the intermediate table name is track_user i am trying to delete the record but unable to do it 

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 Error:

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`))

User Model :

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

Track Model :

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

Controller

//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');
}

Upvotes: 0

Views: 4905

Answers (2)

ivan
ivan

Reputation: 44

From the laravel docs "the opposite of attach is detach:"

Look for it in the http://four.laravel.com/docs/eloquent

Example to leave:

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

Upvotes: 2

David Stanley
David Stanley

Reputation: 11

You have to first delete the record from the composite user_track table. Only then can you delete the parent record in the track table.

Upvotes: 1

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