title: Update a row using idiorm and php
body: <p>I have this function to update a record, but i cannot it fails and send me a "Primary key ID missing from row or is null" message, how can I fix it?</p>
  
  <pre><code>public static function update_child($data)
  {
      try
      {
          $update= ORM::for_table("dm_child",DM_TAG)
                          -&gt;where_equal($data["id_child"]);
  
          $update -&gt; set(array(
              "gender" =&gt; $data["gender"]
              "age_year" =&gt;$data["year"]
              "age_month" =&gt; $data["month"]
  
          ));
          $update -&gt; save();
      }
      catch(PDOException $ex)
      {
          ORM::get_db()-&gt;rollBack();
          throw $ex;
      }
  }
  </code></pre>