title: Return only the newest rows from a BigQuery table with a duplicate items
body: <p>I have a table with many duplicate items – Many rows with the same <code>id</code>, perhaps with the only difference being a <code>requested_at</code> column.</p>
  
  <p>I'd like to do a <code>select *</code> from the table, but only return one row with the same <code>id</code> – the most recently requested.</p>
  
  <p>I've looked into <code>group by id</code> but then I need to do an aggregate for each column. This is easy with <code>requested_at</code> – <code>max(requested_at) as requested_at</code> – but the others are tough.</p>
  
  <p>How do I make sure I get the value for <code>title</code>, etc that corresponds to that most recently updated row?</p>