/** * * @param string $spec Default id field * @return Mzax_Db_Select */ public function group($spec = 1, $clear = false) { if (is_int($spec)) { $spec = new Zend_Db_Expr("{$spec}"); } if ($clear) { $this->reset(self::GROUP); } parent::group($this->_getBindExpr($spec)); return $this; }