Yii:如何在GROUP BY之前使用CDbCriteria进行ORDER BY？

Question

使用这样的查询:

SELECT * FROM (
    SELECT * FROM message ORDER BY added_on DESC
) as m WHERE receiver_id = 2 GROUP BY sender_id ORDER BY priority_id DESC;

我知道如何使用findAllBySql:

$this->findAllBySql(
    'SELECT * FROM (
        SELECT * FROM message ORDER BY added_on DESC
     ) as m WHERE receiver_id = :receiverId 
     GROUP BY sender_id 
     ORDER BY priority_id DESC', 
     array('receiverId' => $userId));

但我想知道是否有任何方法使用CDbCriteria执行此操作导致以下代码,当然,不起作用:

$criteria = new CDbCriteria();
$criteria->condition = 'receiver_id = :receiverId';
$criteria->group = 'sender_id';
$criteria->order = 'priority_id DESC, added_on DESC';
$criteria->params = array('receiverId' => $userId);

谢谢.

Answer 1

我知道为时已晚.我有类似的问题,我尝试这样做

$criteria = new CDbCriteria();
$criteria->select = '*, MAX(added_on) max_added_on';
$criteria->condition = 'receiver_id = :receiverId';
$criteria->group = 'sender_id';
$criteria->order = 'priority_id DESC, max_added_on DESC';
$criteria->params = array('receiverId' => $userId);

它解决了我的问题.如果要检索max_added_on,只需在模型类上添加另一个属性即可.

Answer 2

如果你有一个相当复杂的SQL查询,最好将它保存在SQL中,而不是在Active Record中编写它.是的,它限制了数据库的可移植性,但是您可能没有这些查询,并且更简单,更易维护的代码总是获胜.