title: MySql find_in_set() not playing nice with PHP PDO
body: <p>Any ideas on why the following would be throwing a parameter error. I have taken a look at all the other answers on SO but I am approaching this in the same way as those solutions anyway but this still does not seem to work. Switching an app from adodb to pdo.</p>
  
  <pre><code>$possible_keys = implode( ",", $possible_keys_array );
  </code></pre>
  
  <p>sql snippet</p>
  
  <pre><code>WHERE
  FIND_IN_SET(table.key,:possible_keys)
  
  $STH = $DBH-&gt;prepare( $sql );
  
  $STH-&gt;execute( array( $possible_keys ) );
  
  $STH-&gt;setFetchMode( PDO::FETCH_ASSOC );
  </code></pre>
  
  <p>I have only put in a snap shot of the code. But it all works fine if I replace the :possible_keys place-holder with the actual text of the possible_keys variable. I'm scratching my head as to why this won't work since the variable is just a string anyway. It keeps throwing the following error:</p>
  
  <pre><code>SQLSTATE[HY093]: Invalid parameter number: parameter was not defined
  </code></pre>
  
  <p>p.s. I have only included the clause that is proving to be the problem as opposed to the whole query. I know the rest of it is fine.</p>