title: How to get last inserted id through save() method in laravel
body: <p>I know to get the last id I can use <code>insertGetId()</code> but I want to know how can I get the last inserted id through <code>save()</code> method.</p>
  
  <pre><code>order = new Store_order;
      $order-&gt;invoice_id = $signed['invoice_id'];
      $invoice = $order-&gt;save()['so_id'];
  </code></pre>
  
  <p>I used this but it returns <code>null</code> value</p>