Question

我需要选择学术表中的最后一条记录，其中有两列用于日期和时间。当我运行查询时，我收到一个错误。当未使用EXISTS引入子查询时，只能在选择列表中指定一个表达式。

USE PCUnitTest
SELECT        C.ACCOUNTNO, C.CONTACT, C.LASTNAME, C.KEY4, A.PEOPLE_ID, A.APP_STATUS, A.APP_DECISION, A.REVISION_DATE, A.REVISION_TIME
FROM            ACADEMIC AS A INNER JOIN
                         GM.dbo.CONTACT1 AS C ON A.PEOPLE_ID = C.KEY4
WHERE A.REVISION_DATE = (SELECT     TOP (1) REVISION_DATE, REVISION_TIME, PEOPLE_CODE, PEOPLE_ID, PEOPLE_CODE_ID, ACADEMIC_YEAR, ACADEMIC_TERM, ACADEMIC_SESSION, PROGRAM, DEGREE, CURRICULUM
FROM         PCUnitTest.dbo.ACADEMIC
ORDER BY REVISION_DATE DESC, REVISION_TIME DESC)

Answer 1

使用ROW_NUMBER（）

USE PCUnitTest

SELECT
 R.ACCOUNTNO, R.CONTACT, R.LASTNAME, R.KEY4, R.PEOPLE_ID, R.APP_STATUS, R.APP_DECISION, R.REVISION_DATE, R.REVISION_TIME
FROM
(
SELECT        C.ACCOUNTNO, C.CONTACT, C.LASTNAME, C.KEY4, A.PEOPLE_ID, A.APP_STATUS, A.APP_DECISION, A.REVISION_DATE, A.REVISION_TIME
    ,ROW_NUMBER() OVER (ORDER BY A.REVISION_DATE DESC, A.REVISION_TIME DESC) RN
FROM            ACADEMIC AS A INNER JOIN
                         GMUnitTest.dbo.CONTACT1 AS C ON A.PEOPLE_ID = C.KEY4
) R
WHERE RN=1

如果要获取每个PEOPLE_ID的最新行，请添加PARTITION BY

SELECT
 R.ACCOUNTNO, R.CONTACT, R.LASTNAME, R.KEY4, R.PEOPLE_ID, R.APP_STATUS, R.APP_DECISION, R.REVISION_DATE, R.REVISION_TIME
FROM
(
SELECT        C.ACCOUNTNO, C.CONTACT, C.LASTNAME, C.KEY4, A.PEOPLE_ID, A.APP_STATUS, A.APP_DECISION, A.REVISION_DATE, A.REVISION_TIME
    ,ROW_NUMBER() OVER (PARTITION BY A.PEOPLE_ID ORDER BY A.REVISION_DATE DESC, A.REVISION_TIME DESC) RN
FROM            ACADEMIC AS A INNER JOIN
                         GMUnitTest.dbo.CONTACT1 AS C ON A.PEOPLE_ID = C.KEY4
) R
WHERE RN=1

Answer 2

您可以在

中加入您正在使用的查询

["Split", "this, but not this"]

选择日期和时间列的最后一条记录

2 个答案: