/**
*
* {@inheritDoc}
*/
public function fetchValue(array $params = array())
{
$param_keys_2_exclude = array('limit_offset', 'limit_size');
$query_obj = $this->_buildFetchQueryObjectFromParams($params, $param_keys_2_exclude);
$query_obj->limit(1);
$sql = $query_obj->__toString();
$params_2_bind_2_sql = $query_obj->getBindValues();
$result = $this->_db_connector->dbFetchValue($sql, $params_2_bind_2_sql);
//need to issue a second query to get the number of matching rows
$params['cols'] = array(' COUNT(*) AS num_rows');
$query_obj_4_num_matching_rows = $this->_buildFetchQueryObjectFromParams($params, $param_keys_2_exclude);
$sql = $query_obj_4_num_matching_rows->__toString();
$params_2_bind_2_sql = $query_obj_4_num_matching_rows->getBindValues();
$num_matching_rows = $this->_db_connector->dbFetchOne($sql, $params_2_bind_2_sql);
//return null if there wasn't any matching row
return intval($num_matching_rows['num_rows']) > 0 ? $result : null;
}
