/**
* 某一列唯一的数据
*
* @param string $key
* @param string $query
* @return string
*/
public function distinct($key, $query)
{
$key = is_string($key) ? trim($key) : '';
$query = $this->toArray($query);
$rst = $this->_model->distinct($key, $query);
return $this->result($rst);
}
