sql 怎么查询一个列的最大值
答案:2 悬赏:60 手机版
解决时间 2021-03-03 12:01
- 提问者网友:一抹荒凉废墟
- 2021-03-03 05:13
sql 怎么查询一个列的最大值
最佳答案
- 五星知识达人网友:想偏头吻你
- 2021-03-03 06:50
方法一
SELECt ID ,
Name ,
( SELECT MAX(LastUpdateDate)
FROM ( VALUES ( UpdateByApp1Date), ( UpdateByApp2Date),
( UpdateByApp3Date) ) AS UpdateDate ( LastUpdateDate )
) AS LastUpdateDate
FROM ##TestTable
方法二
SELECt ID ,
[Name] ,
MAX(UpdateDate) AS LastUpdateDate
FROM ##TestTable UNPIVOT ( UpdateDate FOR DateVal IN ( UpdateByApp1Date,
UpdateByApp2Date,
UpdateByApp3Date ) ) AS u
GROUP BY ID ,
Name
方法三
SELECT ID ,
name ,
( SELECT MAX(UpdateDate) AS LastUpdateDate
FROM ( SELECt tt.UpdateByApp1Date AS UpdateDate
UNIOn
SELECT tt.UpdateByApp2Date
UNIOn
SELECT tt.UpdateByApp3Date
) ud
) LastUpdateDate
FROM ##TestTable tt
SELECt ID ,
Name ,
( SELECT MAX(LastUpdateDate)
FROM ( VALUES ( UpdateByApp1Date), ( UpdateByApp2Date),
( UpdateByApp3Date) ) AS UpdateDate ( LastUpdateDate )
) AS LastUpdateDate
FROM ##TestTable
方法二
SELECt ID ,
[Name] ,
MAX(UpdateDate) AS LastUpdateDate
FROM ##TestTable UNPIVOT ( UpdateDate FOR DateVal IN ( UpdateByApp1Date,
UpdateByApp2Date,
UpdateByApp3Date ) ) AS u
GROUP BY ID ,
Name
方法三
SELECT ID ,
name ,
( SELECT MAX(UpdateDate) AS LastUpdateDate
FROM ( SELECt tt.UpdateByApp1Date AS UpdateDate
UNIOn
SELECT tt.UpdateByApp2Date
UNIOn
SELECT tt.UpdateByApp3Date
) ud
) LastUpdateDate
FROM ##TestTable tt
全部回答
- 1楼网友:鱼忧
- 2021-03-03 07:09
select a.id from table a
left outer join
(
select name, max(num) max_num from table
group by name
) b
on a.name = b.name
and a.num = b.max_num
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