有個表USERS如下
Number(int)  Name(char)
1            a
2            b
3            b
4            a
5            c
6            c
要求:當Name列上有相同時,
只保留Number這列上值小的
那一行,結果應如下:
Number(int)  Name(char)
1            a
2            b
5            c
問:用SQL語句的Delete來實現.(記住,是一個SQL語句)


create table #user(number int ,name char(1))
insert into #user select 1,'a'
union all         select 2,'b'
union all         select 3,'b'
union all         select 4,'a'
union all         select 5,'c'
union all         select 6,'c'

delete from #user where number not in(select number from (select min(number)as number,name from #user group by name)as a)
////
下面是plsql實現方法：
Create Table std_user
 (seq Number(10)
 ,std_Name Varchar2(50)
  )
/
Select * From std_user 

Select seq,std_name From std_user
Where seq In(Select min(seq) From std_user
             Group By std_name)
/