使用此 SQL 语句,我可以从所有用户那里获取最新消息:
SELECT m1.*
FROM message AS m1
INNER JOIN user
AS u1
ON m1.sender_id = u1.user_id
INNER JOIN (
SELECT sender_id,
MAX(dateSent) MaxDate
FROM message
WHERE receiver_id = 4
GROUP BY sender_id
) AS m2
ON m1.sender_id = m2.sender_id
AND m1.datesent = m2.MaxDate;
这些是我在 Zend Framework 2 应用程序中的实体:
首先,我收到了消息。一个用户可以向另一个用户发送消息。
/**
* @ORM\Entity
* @ORM\Table(name="message")
*/
class Message
{
/**
* @ORM\Id
* @ORM\GeneratedValue(strategy="AUTO")
* @ORM\Column(type="integer")
*/
private $id;
/**
* @ORM\ManyToOne(targetEntity="Application\Entities\User", inversedBy="messagesSent")
* @ORM\JoinColumn(referencedColumnName="user_id")
*/
private $sender;
/**
* @ORM\ManyToOne(targetEntity="Application\Entities\User", inversedBy="messagesReceived")
* @ORM\JoinColumn(referencedColumnName="user_id")
*/
private $receiver;
/**
* @ORM\Column(type="string", length=1024)
*/
private $message;
和这里的用户实体:
/**
* @ORM\Entity
* @ORM\Table(name="user")
*/
class User
{
/**
* @var int
* @ORM\Id
* @ORM\Column(type="integer")
* @ORM\GeneratedValue(strategy="AUTO")
*/
protected $user_id;
我试图将该SQL 翻译成 DQL并得到这个:
SELECT m1.*
FROM Application\Entities\Message AS m1
INNER JOIN Application\Entities\User AS u1
WITH m1.sender_id = u1.user_id
INNER JOIN (
SELECT sender_id,
MAX(dateSent) MaxDate
FROM Application\Entities\Message
WHERE receiver_id = 4
GROUP BY sender_id
) AS m2
WITH m1.sender_id = m2.sender_id
AND m1.datesent = m2.MaxDate;
如果我执行它,我会从 Doctrine 收到一个错误:
[Semantical Error] line 0, col 206 near '(
': Error: Class '(' is not defined.
我做错了什么?