我有一个登录表，如下所示：
登录表
Emp_ID Created | Action
1 20/01/2016 10:44:42 AM login
1 20/01/2016 4:45:49 PM logout
1 20/01/2016 6:30:13 PM logout
1 21/01/2016 8:46:28 AM login
1 21/01/2016 9:46:42 AM login
1 21/01/2016 1:46:46 PM logout
1 22/01/2016 8:49:21 AM login
1 22/01/2016 1:49:27 PM logout
1 22/01/2016 2:29:53 PM login
1 22/01/2016 2:30:13 PM logout
3 22/01/2016 2:42:06 PM login
1 22/01/2016 9:57:22 PM login
1 22/01/2016 10:22:23 PM logout
1 23/01/2016 8:01:47 AM login
1 23/01/2016 9:01:58 AM logout
3 23/01/2016 8:02:06 AM login
3 23/01/2016 9:02:28 AM logout
员工表
| ID | Fname | Lname |
|----|-------|-------|
| 1 | James | Brown |
| 2 | Mark | Bond |
| 3 | Kemi | Ojo |
我得到的结果
| created | login | logout | Employee | Emp_ID |
|------------|----------|----------|-------------|--------|
| 2016-01-20 | 10:44:42 | 18:30:13 | James Brown | 1 |
| 2016-01-21 | 08:46:28 | 13:46:46 | James Brown | 1 |
| 2016-01-22 | 08:49:21 | 22:22:23 | James Brown | 1 |
| 2016-01-22 | 14:42:06 | 22:22:23 | Kemi Ojo | 3 |
| 2016-01-23 | 08:01:47 | 09:02:28 | James Brown | 1 |
| 2016-01-23 | 08:02:06 | 09:02:28 | Kemi Ojo | 3 |
以下是我的尝试：
SELECT
CAST(LI.created AS DATE) AS created,
MIN(CAST(LI.created AS TIME)) AS login,
MAX(CAST(LO.created AS TIME)) AS logout,
e.fname+' '+e.lname Employee, li.Emp_ID
FROM
Logins LI
LEFT OUTER JOIN Logins LO ON
LO.action = 'logout' AND
CAST(LO.created AS DATE) = CAST(LI.created AS DATE)
JOIN dbo.Employees AS E ON E.ID = li.Emp_ID
WHERE
LI.action = 'login'
GROUP BY
CAST(LI.created AS DATE), E.fname + ' ' + E.lname, li.Emp_ID
但结果不正确。
请注意，不同用户的最后两个结果是相同的。例如09:02:28出现两次而不是9:01:58
此外，对于没有注销emp_id = 3的登录，我遇到了问题。当应用程序意外关闭时会发生这种情况。
3如何在没有注销的情况下放置00:00:00 4.或者你对这种情况下该怎么做的建议是什么？
我需要选择一个如下所示的结果集：
| created | login | logout | Employee | Emp_ID |
|------------|----------|----------|-------------|--------|
| 2016-01-20 | 10:44:42 | 18:30:13 | James Brown | 1 |
| 2016-01-21 | 08:46:28 | 13:46:46 | James Brown | 1 |
| 2016-01-22 | 08:49:21 | 22:22:23 | James Brown | 1 |
| 2016-01-22 | 14:42:06 | 00:00:00 | Kemi Ojo | 3 |
| 2016-01-23 | 08:01:47 | 09:01:58 | James Brown | 1 |
| 2016-01-23 | 08:02:06 | 09:02:28 | Kemi Ojo | 3 |
答案 0 :(得分：3)
首先，对完美问题的赞誉。表结构，小提琴演示和预期输出有很大帮助。
现在我尝试了这个，它正在努力工作。请重新检查并告诉我。
select t_login.emp_id,t_login.dt_created as created,t_login.login,
case when t_logout.logout is null
then cast('00:00:00' as time)
else t_logout.logout end as logout,
e.fname+' '+e.lname Employee
from
(select emp_id,CAST(created AS DATE) AS dt_created,
MIN(CAST(created AS TIME)) as login
from logins
where action='login'
group by emp_id,CAST(created AS DATE)) t_login
left join
(select emp_id,CAST(created AS DATE) AS dt_created,
max(CAST(created AS TIME)) as logout
from logins
where action='logout'
group by emp_id,CAST(created AS DATE)) t_logout
on t_login.emp_id=t_logout.emp_id
and t_login.dt_created=t_logout.dt_created
inner join
employees e
on e.id=t_login.emp_id
PS：这不会处理特定日期没有登录且仅注销的情况。如果您需要，请使用full outer join并使用与我在case子句中使用的select语句相同的语句。
请参阅此处的小提琴演示
http://sqlfiddle.com/#!3/465f0/34
输出继电器
+---------+-------------+-------------------+-------------------+-------------+
| emp_id | created | login | logout | Employee |
+---------+-------------+-------------------+-------------------+-------------+
| 1 | 2016-01-20 | 10:44:42.0000000 | 18:30:13.0000000 | James Brown |
| 1 | 2016-01-21 | 08:46:28.0000000 | 13:46:46.0000000 | James Brown |
| 1 | 2016-01-22 | 08:49:21.0000000 | 22:22:23.0000000 | James Brown |
| 3 | 2016-01-22 | 14:42:06.0000000 | 00:00:00.0000000 | Kemi Ojo |
| 1 | 2016-01-23 | 08:01:47.0000000 | 09:01:58.0000000 | James Brown |
| 3 | 2016-01-23 | 08:02:06.0000000 | 09:02:28.0000000 | Kemi Ojo |
+---------+-------------+-------------------+-------------------+-------------+
答案 1 :(得分：3)
这是我的建议（请注意特定于文化的日期文字。我必须设置一种语言才能获得正确的日期转换）：
SET LANGUAGE GERMAN;
DECLARE @logins TABLE(Emp_ID INT,Created DATETIME, Action VARCHAR(100));
INSERT INTO @logins VALUES
(1,'20/01/2016 10:44:42 AM','login')
,(1,'20/01/2016 4:45:49 PM','logout')
,(1,'20/01/2016 6:30:13 PM','logout')
,(1,'21/01/2016 8:46:28 AM','login')
,(1,'21/01/2016 9:46:42 AM','login')
,(1,'21/01/2016 1:46:46 PM','logout')
,(1,'22/01/2016 8:49:21 AM','login')
,(1,'22/01/2016 1:49:27 PM','logout')
,(1,'22/01/2016 2:29:53 PM','login')
,(1,'22/01/2016 2:30:13 PM','logout')
,(3,'22/01/2016 2:42:06 PM','login')
,(1,'22/01/2016 9:57:22 PM','login')
,(1,'22/01/2016 10:22:23 PM','logout')
,(1,'23/01/2016 8:01:47 AM','login')
,(1,'23/01/2016 9:01:58 AM','logout')
,(3,'23/01/2016 8:02:06 AM','login')
,(3,'23/01/2016 9:02:28 AM','logout');
DECLARE @employees TABLE(ID INT,Fname VARCHAR(100),Lname VARCHAR(100));
INSERT INTO @employees VALUES
(1,'James','Brown')
,(2,'Mark','Bond')
,(3,'Kemi','Ojo');
WITH Logins AS
(
SELECT
MIN(PureDate) AS Created
,MIN(CAST(l.Created AS TIME)) AS LoginTime
,l.Emp_ID
FROM @logins AS l
CROSS APPLY(SELECT CAST(l.Created AS DATE) PureDate) AS Created
WHERE l.Action ='login'
GROUP BY l.Emp_ID,PureDate
)
,Logouts AS
(
SELECT
MAX(PureDate) AS Created
,MAX(CAST(l.Created AS TIME)) AS LogoutTime
,l.Emp_ID
FROM @logins AS l
CROSS APPLY(SELECT CAST(l.Created AS DATE) PureDate) AS Created
WHERE l.Action ='logout'
GROUP BY l.Emp_ID,PureDate
)
SELECT Logins.Created
,Logins.LoginTime
,ISNULL(Logouts.LogoutTime,'00:00:00')
,e.Lname
,e.ID
FROM Logins
INNER JOIN @employees AS e ON e.ID = Logins.Emp_ID
LEFT JOIN Logouts ON Logins.Emp_ID = Logouts.Emp_ID
AND Logins.Created = Logouts.Created
ORDER BY Created,LoginTime
结果
2016-01-20 10:44:42 18:30:13 Brown 1
2016-01-21 08:46:28 13:46:46 Brown 1
2016-01-22 08:49:21 22:22:23 Brown 1
2016-01-22 14:42:06 00:00:00 Ojo 3
2016-01-23 08:01:47 09:01:58 Brown 1
2016-01-23 08:02:06 09:02:28 Ojo 3
答案 2 :(得分：2)
你错过了LO表和LI表之间的JOIN：
AND LO.Emp_ID = LI.Emp_ID
我认为你可以在不使用自我加入的情况下使用CASE WHEN来做到这一点，我觉得它会更漂亮，但尝试这个补充。
评论编辑： 只需更换： MAX（CAST（LO.Created AS时间）） ...有： MAX（CAST（isnull（LO.Created，'00：00：00'）AS时间））