Question

我有一张表EmployeeDetails

DeptID   |       workDate       |  percentage
------------------------------------------
1           06/07/16 10:10:10      10%
1           07/07/16 11:11:10      20%
2           06/07/16 09:10:10      5%
2           07/07/16 08:10:10      3%
3           06/07/16 10:10:10      15%
4           07/07/16 11:10:10      20%

你能不能帮我找一个sql查询来查找＆＃39; workDate＆＃39;的最大日期时间。然后根据＆＃39; workDate＆＃39;获得每个部门的相应记录。

预期产出：

DeptID    | workDate |       percentage 
1       07/07/16 11:11:10     20% 
2       07/07/16 08:10:10     3% 
3       06/07/16 10:10:10    15% 
4       07/07/16 11:10:10    20%

非常感谢。

Answer 1

请参阅下文。在这种情况下，内部联接将有所帮助。

CREATE TABLE #EmployeeDetails
(
    DeptID int
    ,workDate datetime
    ,percentage varchar(100)
)

INSERT INTO #EmployeeDetails
SELECT 1,'06/07/16 10:10:10','10%'
UNION
SELECT 1,'07/07/16 11:11:10','20%'
UNION
SELECT 2,'06/07/16 09:10:10','5%'
UNION
SELECT 2,'07/07/16 08:10:10','3%'
UNION
SELECT 3,'06/07/16 10:10:10','15%'
UNION
SELECT 4,'07/07/16 11:10:10','20%'

SELECT   T1.* 
FROM     #EmployeeDetails T1
JOIN    (SELECT DeptID,MAX(workDate) AS max_workdate
         From #EmployeeDetails
         GROUP BY DeptID) T2 
ON       T1.DeptID = T2.DeptID AND T1.workDate = T2.max_workdate
ORDER BY T1.DeptID

根据最大日期查找最大记录

1 个答案: