function addAnd($left, $right = null, $operator = Query::EQUAL, $quote = null) {
		if (null === $left) {
			return $this;
		}

		if (is_array($left)) {
			foreach ($left as $key => &$value) {
				$this->addAnd($key, $value);
			}
			return $this;
		}

		$this->conds[] = array('AND', func_get_args());
		return $this;
	}