title: Wordpress: update custom field 1 if custom field 2 gets deleted at backend
body: <p>Is there a simple way to udpate a specific custom field (post_meta) of a wordpress &quot;page&quot; at the backend, if an other one gets deleted?</p>
  <p>For example, I have the following custom fields (at a page) in the backend:</p>
  <pre><code>&quot;Score&quot; (key) -&gt; &quot;2&quot; (Value)
  &quot;Score&quot; (key) -&gt; &quot;1&quot; (Value)
  &quot;Score_Total&quot; (key) -&gt; &quot;3&quot; (Value)
  </code></pre>
  <p>So, if I delete the custom field with the value &quot;2&quot; the &quot;Score_Total&quot; needs to updated to &quot;1&quot;.</p>
  <p>I know this for the frontend:</p>
  <pre><code>update_post_meta($post_id,'Score_Total',count( $count ));
  </code></pre>
  <p>But how will this work at backend by just deleting a custom field?</p>
  <p>Or is there a detection of deleting a &quot;custom field&quot; (post_meta) at backend?</p>