title: DynamoDB: Expected value operators for deleteItem (or putItem) calls?
body: <p>I am trying to add a condition to a <code>deleteItem</code> call that will be evaluated prior to deleting the item. (For the sake of this example, the DynamoDB table name is <code>TABLE_NAME</code>).</p>
  
  <pre><code>TABLE_NAME.imported_timestamp value is less than timestamp of 60 days ago
  </code></pre>
  
  <p>I could have sworn there is a way to do this, but I haven't been able to find any definitive documentation or discussion on the matter. The following PHP code block is what I have right now.. </p>
  
  <pre><code>$cmp_timestamp = strtotime('-60 days');
  $dynamo-&gt;deleteItem(array(
      'TableName' =&gt; 'TABLE_NAME',
      'Key' =&gt; array(
          'HashKeyElement' =&gt; array('S' =&gt; 'my_hash_key_element')
      ),
      'Expected' =&gt; array(
          'imported_timestamp' =&gt; array('Value' =&gt; array('N' =&gt; $cmp_timestamp))
      )
  ));
  </code></pre>
  
  <p>Currently, the above code will check if <code>TABLE_NAME.imported_timestamp</code> value is equal to the value of <code>$cmp_timestamp</code>. Any help or suggestion is greatly appreciated!</p>