New record and many to many insert - mysql

Question

I am working in a project where the users have a rate plan associated. When a new user is created, a valid rate plan must be specified.
I have the following MySQL schema and Eloquent models:
/**
* User Eloquent model file ...
*
*/
public function ratePlans() {
return $this->belongsToMany(
'App\Models\RatePlan',
'users_rate_plans',
'users_id',
'rate_plans_id'
);
}
So, to create a new user with your selected rate plan i do:
try {
\DB::beginTransaction();
$model->create($data);
$model->ratePlans()->attach($data['rate_plan'], ['active' => 1]);
\DB::commit();
return $model;
} catch(\Exception $e) {
\DB::rollback();
return false;
}
But, i am getting the next exception:
SQLSTATE[23000]: Integrity constraint violation: 1048 Column
'users_id' cannot be null (SQL: insert into users_rate_plans
(active, rate_plans_id, users_id) values (1, 43, ))
Why te transaction didn't work ? How i can do that task ?
UPDATE 1
I changed the transaction code but, the result is the same.
try {
\DB::beginTransaction();
$ratePlan = \App\Models\RatePlan::find($data['rate_plan']);
$user->ratePlans()->attach($ratePlan, ['active' => 1]);
$user->create($data);
\DB::commit();
return $user;
} catch(\Exception $e) {
\DB::rollback();
die($e->getMessage());
return false;
}
UPDATE 2
I changed the transaction code again and its works:
\DB::beginTransaction();
$user = \App\Models\User::create($data);
$ratePlan = \App\Models\RatePlan::find($data['rate_plan']);
$user->ratePlans()->attach($ratePlan, ['active' => 1]); \DB::commit();
return $user;

Answer 1

I think you're not loading the rate_plans entity.
$model->ratePlans()->attach($data['rate_plan'], ['active' => 1]);
In this line $data['rate_plan'] shoud be an instance of your model "rate_plans", and I'm assuming that $model in this situation stand for an entity of your User model
Also have tried a test without the transaction if the result's is the same ?
I give you an example of one of my code which is similar:
try {
DB::beginTransaction();
$group = Group::create($data);
$employees = User::whereIn('reference', $references)->get();
$group->employees()->attach($employees);
$group->save();
DB::commit();
} catch(Exception $e) { [...] }
Good luck