public function fetchColumn($sql, array $params = array(), $pos = 0)
    {
        return $this->run($sql, $params)->fetchColumn($pos);
    }
public function fetchColumn($sql, array $params = array(), $pos = 0)
    {
        return $this->run($sql, $params)->fetchColumn($pos);
    }
public function fetchColumn ( $ sql , array $ params = array ( ) , $ pos = 0 ) { return $ this -> run ( $ sql , $ params ) -> fetchColumn ( $ pos ) ; }
Returns a single column
@param string $sql
@param array $params
@param integer $pos
@return mixed
Returns a single column