MySQL子查询计算

Question

我有这个MySQL查询，当我搜索一个用户，他有一个登录（开始 - 结束）它显示下一行的总数好，但如果用户有多个登录（开始 - 结束）它不显示总的下一行....

SELECT CONCAT(u.lastname, ', ', u.firstname) AS Name 
    , start.timestamp start 
    , end.timestamp end 
    , timediff(end.timestamp, start.timestamp) duration 
FROM user u 
    , user_group ug 
    , (
     select * 
     , (
      select event_id 
      from event L2 
      where L2.timestamp > L1.timestamp 
       and L2.user_bannerid = L1.user_bannerid 
      order by timestamp limit 1 
      ) stop_id 
     From event L1 
    ) start 
join event end on end.event_id = start.stop_id 
where start.status = 'In' 
    and end.status='Out' 
    and u.user_bannerid = start.user_bannerid 
    and ug.user_bannerid = u.user_bannerid 
    and ug.group_id = start.group_id 

UNION 

SELECT null, null, null, CAST(sum(duration) as Time) 
FROM 
(
    SELECT CONCAT(u.lastname, ', ', u.firstname) AS Name 
     , start.timestamp start 
     , end.timestamp end 
     , timediff(end.timestamp, start.timestamp) duration 
    from user u 
     , user_group ug 
     , (
     select * 
     , (
      select event_id 
      from event L2 
      where L2.timestamp > L1.timestamp 
       and L2.user_bannerid = L1.user_bannerid 
      order by timestamp 
      limit 1 
      ) stop_id 
     from event L1 
     ) start 
    join event end on end.event_id = start.stop_id 
    where start.status = 'In' 
     and end.status = 'Out' 
    and u.user_bannerid = start.user_bannerid 
    and ug.user_bannerid = u.user_bannerid 
     and ug.group_id = start.group_id 
) total 

它显示总好吗当用户只需登录一次

+----------------------------------------------------+---------------+ 
| Name | start    | end     | duration  |  
+----------------------------------------------------+---------------+ 
| User | 2011-11-24 02:12:05 | 2011-11-24 02:12:20 | 00:00:15  |  
|  |      |      | 00:00:15  | 
+----------------------------------------------------+---------------+ 

但是，当用户有不止一个登录，它不显示总小时数，

+----------------------------------------------------+---------------+ 
    | Name | start    | end     | duration  |  
    +----------------------------------------------------+---------------+ 
    | User | 2011-11-24 02:12:05 | 2011-11-24 02:12:20 | 00:00:15  |  
    | User | 2011-11-28 21:46:54 | 2011-11-28 21:53:01 | 00:06:17  | 
    |  |      |      |    | 
    +----------------------------------------------------+---------------+ 

即时猜测它必须与限制，但如果我将限制超过1我得到“的错误没有1242子查询返回多个行。”有人可以帮我改写查询来显示总小时数，无论他们有多少登录名？

编辑：

仍然有，所以我想出了一个新的查询，但后来我不断收到的无效，而不是总有这样的问题。 任何想法，为什么这样呢？

+----------------------------------------------------+---------------+ 
| Name | start    | end     | duration  |  
+----------------------------------------------------+---------------+ 
| User | 2011-11-24 02:12:05 | 2011-11-24 02:12:20 | 00:00:15  |  
| User | 2011-11-28 21:46:54 | 2011-11-28 21:53:01 | 00:06:17  | 
| User | 2011-11-28 21:46:54 | 2011-11-28 21:53:01 | null   | 
+----------------------------------------------------+---------------+ 

SELECT 
    CONCAT(u.lastname, ', ', u.firstname) AS Name, 
    start.timestamp AS start, 
    end.timestamp AS end, 
    TIME(SUM(TIMEDIFF(end.timestamp, start.timestamp))) AS duration 
FROM user AS u 
    INNER JOIN user_group AS ug ON u.user_bannerid = ug.user_bannerid 
    INNER JOIN event AS start ON start.user_bannerid = u.user_bannerid AND start.status='In' AND start.group_id = ug.group_id 
    INNER JOIN event AS end ON end.user_bannerid = u.user_bannerid AND end.status='Out' AND start.event_id < end.event_id 
GROUP BY start.event_id WITH ROLLUP 

Answer 1

我觉得你最好的选择将是一个stop_id添加到事件表，那么当用户注销时，更新事件从脱离事故记录ID。

对于现有记录，您可以编写一个查询来根据问题中的逻辑更新记录。

一旦你这样做了，因为你在事件表中有一个stop_id，获取开始和结束时间是一个相对简单的查询。

离开了现在的用户信息，这是所有你需要了解详细内容：

SELECT start.timestamp start , 
     end.timestamp end , 
     timediff(end.timestamp, start.timestamp) duration 
    FROM event start join event end on end.event_id = start.stop_id 

你并不需要测试的启动或停止状态，因为可能只有一个状态这些事件In将有一个stop_id和内部联接（假设这是mysql中的联接）防止Out记录被包含在顶层。