表结构id tag hits bussinessid 1 a 20 1 2 b 30 1 3 c 40 1 4 a 40 1要得到结果id tag hits bussinessid 1 a 20 1 2 b 30 1 3 c 40 1
--方法一 Select * From 表 A Where id In (Select Max(id) From 表 Group By tag)--方法二 Select A.* From 表 A Inner Join (Select tag, Max(id) As id From 表 Group By tag) B On A.tag = B.tag And A.id = B.id--方法三 Select * From 表 A Where Not Exists(Select id From 表 Where tag = A.tag And id > A.id)--方法四 Select * From 表 A Where id = (Select Max(id) From 表 Where tag = A.tag)
寫錯了,改寫--方法一 Select * From 表 A Where id In (Select Min(id) From 表 Group By tag)--方法二 Select A.* From 表 A Inner Join (Select tag, Min(id) As id From 表 Group By tag) B On A.tag = B.tag And A.id = B.id--方法三 Select * From 表 A Where Not Exists(Select id From 表 Where tag = A.tag And id < A.id)--方法四 Select * From 表 A Where id = (Select Min(id) From 表 Where tag = A.tag)
表结构id tag hits bussinessid
1 a 20 1
2 b 30 1
3 c 40 1
4 a 40 1要得到结果id tag hits bussinessid
1 a 20 1
2 b 30 1
3 c 40 1
Select * From 表 A Where id In (Select Max(id) From 表 Group By tag)--方法二
Select A.* From 表 A
Inner Join
(Select tag, Max(id) As id From 表 Group By tag) B
On A.tag = B.tag And A.id = B.id--方法三
Select * From 表 A Where Not Exists(Select id From 表 Where tag = A.tag And id > A.id)--方法四
Select * From 表 A Where id = (Select Max(id) From 表 Where tag = A.tag)
Select * From 表 A Where id In (Select Min(id) From 表 Group By tag)--方法二
Select A.* From 表 A
Inner Join
(Select tag, Min(id) As id From 表 Group By tag) B
On A.tag = B.tag And A.id = B.id--方法三
Select * From 表 A Where Not Exists(Select id From 表 Where tag = A.tag And id < A.id)--方法四
Select * From 表 A Where id = (Select Min(id) From 表 Where tag = A.tag)