Laravel 4: Save polymorphic relationship - php

Question

I'm trying to save a polymorphic relationship in laravel and can't get it to work. I either get this error: Call to undefined method Illuminate\Database\Query\Builder::save() if I do $user->provider()->save($provider)
Or I get
SQLSTATE[42S22]: Column not found: 1054 Unknown column 'userable_type' in 'field list' (SQL: insert into 'providers' ('user_id', 'userable_type', 'userable_id') values (16, Provider, 16))
if I switch it around and do $provider->user()->save($provider); as suggested in Call to undefined Builder::save() when saving a polymorphic relationship
From what little documentation I could find on polymorphic relationships, it seems the userable_type/id stuff goes in the parent table, and since User is my parent table, rather than Provider, the 2nd method seems to be the wrong way to do it.
At a guess I'd say the problem is with my morphTo/morphOne methods, but I've no clue how to fix them since the documentation for those methods has nothing to say about their parameters. My provider table might be set up a bit differently from what laravel expects, since it doesn't have an incremental id field as the primary key; the primary key is the foreign key and is named user_id.
This is my register code:
public function postRegister()
{
$input = Input::all();
$user = $this->user;
$validator = Validator::make($input, $user::$rules);
if($validator->passes())
{
$user->username = $input['username'];
$user->email = $input['email'];
$user->password = Hash::make($input['password']);
$user->save();
if($input['account_type'] == 0)
{
$provider = new Provider();
$provider->user_id = $user->id;
//$provider->user()->save($provider);
$user->provider()->save($provider);
}
return 'Success';
}
else
{
return Redirect::back()->withInput($input)->withErrors($validator->messages());
}
}
User model:
<?php
class User extends Validatable implements UserInterface, RemindableInterface
{
use UserTrait, RemindableTrait;
protected $table = 'users';
public function userable()
{
return $this->morphTo();
}
}
Provider Model:
<?php
class Provider extends Validatable
{
protected $table = 'providers';
protected $primaryKey = 'user_id';
public $timestamps = false;
public function user()
{
return $this->morphOne('User', 'userable');
}
}

Answer 1

You can call it like this:
$provider->user()->save($user);