SQL取聊天消息列表

 SELECT count(`read` = 0 or null) AS newMessage, 
            receiver,content,newTable.inputTime, u.name, u.img 
 FROM
     (SELECT receiver_id as receiver,content,`read`,inputTime FROM chat
     WHERE
     (sender_id = 91) AND (receiver_id <> 91)
     UNION 
     SELECT sender_id as receiver,content,`read`,inputTime FROM chat
     WHERE 
     (sender_id <> 91) AND (receiver_id = 91)
     ORDER BY inputTime DESC) as newTable
 INNER JOIN 
 user u on receiver = u.id 
 GROUP BY receiver 
 ORDER BY inputTime DESC
 LIMIT 0, 10