--建立测试环境 Create table TEST (col1 Varchar(10), col2 Int, col3 Int) --插入数据 Insert TEST Values('A', 3, 3) Insert TEST Values('A', 4, 4) Insert TEST Values('B', 4, 4) --测试 Select (Case When Exists(Select * from TEST Where col1=A.col1 And Col2<A.Col2) Then '' Else col1 End )As col1, col2, col3 from TEST A --删除测试环境 Drop table TEST --结果 /* col1 col2 col3 A 3 3 4 4 B 4 4 */
Select
(Case When Exists(Select * from TableName Where col1=A.col1 And Col2<A.Col2) Then '' Else col1 End )As col1,
col2,
col3
from TableName A
select co11,co12,co13 from table group by co11
------------------------
语法是错的
Create table TEST
(col1 Varchar(10),
col2 Int,
col3 Int)
--插入数据
Insert TEST Values('A', 3, 3)
Insert TEST Values('A', 4, 4)
Insert TEST Values('B', 4, 4)
--测试
Select
(Case When Exists(Select * from TEST Where col1=A.col1 And Col2<A.Col2) Then '' Else col1 End )As col1,
col2,
col3
from TEST A
--删除测试环境
Drop table TEST
--结果
/*
col1 col2 col3
A 3 3
4 4
B 4 4
*/