public function getCol()
	{
		$ret   = array();
		$query = $this->prepareQuery(func_get_args());
		if ( $res = $this->rawQuery($query) )
		{
			while($row = $this->fetch($res))
			{
				$ret[] = reset($row);
			}
			$this->free($res);
		}
		return $ret;
	}