sql 查询的问题
create table mytable(column1 int,column2 int)
insert into mytable values(1,1)
insert into mytable values(2,2)
insert into mytable values(3,3)
insert into mytable values(4,4)
insert into mytable values(5,5)
declare @a int
set @a = 1
select column1 from mytable
我想当@a=1时只查询column1,当@a=2只查询column2,当@a=3时查询2列。我不想用动态的sql语句，因为真实的查询已经写好了，改成动态很困难。 请帮忙看一下
[解决办法]
create table mytable(column1 int,column2 int)
insert into mytable values(1,1)
insert into mytable values(2,2)
insert into mytable values(3,3)
insert into mytable values(4,4)
insert into mytable values(5,5)
declare @a int
set @a = 1
select (Case @a When 1 Then column1 When 2 Then column2 End) As [column] from mytable
Drop Table mytable
