按日期选择相同组的列到不同的列

Question

我登录的表看起来像这样：

Created    | Action 
20/01/2016 08:00:00 AM login 
20/01/2016 10:05:10 AM logout 
20/01/2016 12:00:00 PM login 
20/01/2016 04:12:22 PM logout 
21/01/2016 08:00:50 AM login 
21/01/2016 09:44:42 AM login 
21/01/2016 10:44:42 AM login 
21/01/2016 04:00:42 PM logout 

我需要选择一个结果集，看起来像这样：

Created  | Login | Logout   
20/01/2016  08:00:00 AM 04:12:22 PM 
21/01/2016  08:00:50 PM 04:00:42 PM 

这里是我曾尝试过的：

SELECT 
    CONVERT(VARCHAR(10),li.Created,10) [Date], 
    CONVERT(VARCHAR(8),MAX(li.Created),8) [Login], 
    CONVERT(VARCHAR(8),MAX(lo.Created),8) [Logout] 
FROM Logins li 
LEFT JOIN Logins lo ON lo.[Action] = 'logout' 
GROUP BY li.Created 

但是结果没有按日期分组。

什么是正确的方法？

Answer 1

与Rahul的回答类似，但您可以自行加入以获取第一次登录/最后一次登出，并按日期分组以获得您要求的结果;

SELECT CONVERT(DATE,  li.created) [Date], 
     CONVERT(TIME, MIN(li.created)) [Login], 
     CONVERT(TIME, MAX(lo.created)) [Logout] 
FROM Logins li 
JOIN Logins lo 
    ON CONVERT(DATE, li.created) = CONVERT(DATE, lo.created) 
AND li.action = 'login' 
AND lo.action = 'logout' 
GROUP BY CONVERT(DATE, li.created) 

An SQLfiddle to test with。

编辑：未经测试的SQL Server 2005，您可能需要设置varchars的长度;

SELECT CONVERT(VARCHAR, li.created, 110) [Date], 
     CONVERT(VARCHAR, MAX(li.created), 8) [Login], 
     CONVERT(VARCHAR, MAX(lo.created), 8) [Logout] 
FROM Logins li 
JOIN Logins lo 
    ON CONVERT(VARCHAR, li.created, 110) = CONVERT(VARCHAR, lo.created, 110) 
AND li.action = 'login' 
AND lo.action = 'logout' 
GROUP BY CONVERT(VARCHAR, li.created, 110) 

Another SQLfiddle。

Answer 2

你可以尝试这样的：

SELECT 
CONVERT(VARCHAR(10),li.Created,10) [Date], 
CONVERT(VARCHAR(8),MAX(li.Created),8) [Login], 
CONVERT(VARCHAR(8),MAX(lo.Created),8) [Logout] 
From Logins li 
Left Join Logins lo on lo.[Action] = 'logout' 
GROUP BY CAST(li.Created AS DATE) 

即，你需要按您的记录上的日期，而不是按日期和时间两者。

Answer 3

我打算假设您的结果20日上午4点注销是一个疏忽，否则我们需要知道确定它应该被视为当天注销时间的逻辑。

一个问题是，您试图仅显示日期作为您的组，但您按照日期和时间进行分组。

试试这个：

SELECT 
    CAST(LI.created AS DATE) AS created, 
    MIN(CAST(LI.created AS TIME)) AS login, 
    MAX(CAST(LO.created AS TIME)) AS logout 
FROM 
    dbo.My_Table LI 
LEFT OUTER JOIN dbo.My_Table LO ON 
    LO.action = 'logout' AND 
    CAST(LO.created AS DATE) = CAST(LI.created AS DATE) 
WHERE 
    LI.action = 'login' 
GROUP BY 
    CAST(LI.created AS DATE) 

另一个要考虑的是，是否登录时间可以跨越的日期范围。如果这是科技行业的话，登录1/20晚上10点和登出1/21凌晨2点并不奇怪。 ;）