title: Laravel belongsTo returning null when using 'with'
body: <p>I'm just getting started with Laravel so please forgive any noobness.</p>
  
  <p>I have a <code>User</code> and <code>Order</code> model, a user has many orders:</p>
  
  <pre><code># Inside User model
  public function orders()
  {
      $this-&gt;hasMany('Order');
  } 
  
  # Inside Order
  public function user()
  {
      return $this-&gt;belongsTo('User');
  }
  
  // Not sure if this is upsetting anything (also in Order)
  public function products()
  {
      return $this-&gt;belongsToMany('Product');
  }
  </code></pre>
  
  <p>So I think I have the above right.</p>
  
  <p>But when I do this:</p>
  
  <pre><code> $users = User::with('orders')-&gt;find(1);
   return $users;
  </code></pre>
  
  <p>I get <code>Call to a member function addEagerConstraints() on null</code>.</p>
  
  <p>However, if I do it the other way around, it works great:</p>
  
  <pre><code>$orders = Order::with('User')-&gt;get();
  return $orders;
  </code></pre>
  
  <p>What am I doing wrong / what don't I understand?! Or is my problem bigger than I think?</p>
  
  <p>Database:</p>
  
  <p><img src="https://i.stack.imgur.com/vSgF2.png" alt="enter image description here"></p>