title: mysql CONCAT(): Unknown column ''-'' in 'field list'
body: <p>I am trying to get this: <code>2014-3</code> from the following query:</p>
  
  <pre><code>$this-&gt;db-&gt;select("CONCAT(YEAR(start_date),'-',MONTH(start_date)) yearmonth")
  -&gt;from("events")
  -&gt;where("event_id", 5)-&gt;get();
  </code></pre>
  
  <p>Am i using the concatenation function in a wrong way? please help!</p>