保存多对多关系时Laravel违反完整性约束

Question

When storing a new user and then syncing some many to many relationships I get an integrity constraint error as the ID of the newly created user seems to not be passed to the sync() method. Here is my store controller method:

$user = new User;
$user->name = Input::get('name');
$user->username = Input::get('username');
$user->email = Input::get('email');
$user->password = Input::get('password');
$user->save();

// See if roles are passed, if not assign the default role of "view_site"
$roles = Input::has('roles') ? Input::get('roles') : [3];
$user->roles()->sync($roles);

As you can see I call save() before trying to sync the related data so it should have an ID. Here is the error:

Integrity constraint violation: 1048 Column 'user_id' cannot be null (SQL: insert into users_roles ( role_id , user_id ) values (3, ))

If I run the sync method on an already existent user ( User::find($id)->roles()->sync([1,2,3]) ) it works fine.

For reference, the relationships:

// User.php
public function roles()
{
    return $this->belongsToMany('Role', 'users_roles');
}
// Role.php
public function users()
{
    return $this->belongsToMany('User', 'users_roles');
}

Edit:

Query log prior to the sync() . Looks like the save() is not writing to the database...

Array
(
    [0] => Array
        (
            [query] => select * from `users` where `id` = ? limit 1
            [bindings] => Array
                (
                    [0] => 1
                )

            [time] => 0.63
        )

    [1] => Array
        (
            [query] => select `roles`.*, `users_roles`.`user_id` as `pivot_user_id`, `users_roles`.`role_id` as `pivot_role_id` from `roles` inner join `users_roles` on `roles`.`id` = `users_roles`.`role_id` where `users_roles`.`user_id` = ?
            [bindings] => Array
                (
                    [0] => 1
                )

            [time] => 0.58
        )

    [2] => Array
        (
            [query] => select count(*) as aggregate from `users` where `email` = ? or `username` = ?
            [bindings] => Array
                (
                    [0] => test@example.com
                    [1] => example
                )

            [time] => 0.48
        )

)

Answer 1

Since you are using confide , the validation is based on Ardent . In your store method, add if statement

if($user->save());
    $roles = Input::has('roles') ? Input::get('roles') : [3];
    $user->roles()->sync($roles);
}else{
    return Redirect::back()->withErrors($user->errors());
}

If you don't need to check validation , you may use

$user->forceSave();