sql中case的应用

[sailormars]

declare @sex nvarchar(50)
select @sex = TitleOfCourtesy from dbo.Employees
print @sex
--case 的使用
declare @sex nvarchar(50)
select @sex = TitleOfCourtesy from dbo.Employees
where EmployeeID = 5
case @sex
when 'Ms.' then print'女士'
when 'Mr.' then print'男士'
else print'nothing'
end
请问这样用错误在哪里?

[kk19840210]

declare   @sex   nvarchar(50) 
select top 1  @sex   =   TitleOfCourtesy   from   dbo.Employees 
print   @sex 
--case   的使用     
declare   @sex   nvarchar(50) 
select  top 1 @sex   =   TitleOfCourtesy   from   dbo.Employees 
        where   EmployeeID   =   5 

select case   @sex 
when   'Ms.'   then   print'女士' 
when   'Mr.'   then   print'男士' 
else   print'nothing' 
end 

[dawugui]

select TitleOfCourtesy = case TitleOfCourtesy when 'Ms.' then 女士' when 'Mr.' then '男士'  end from dbo.Employees 

[sailormars]

1楼的根本不对,执行报错
2楼的,我就想用我那种用法,可以用吗?

[pt1314917]

如果要简洁，二楼的已经够了。
楼主是要将你的改成这样？
declare   @sex   nvarchar(50) 
select   @sex   =   TitleOfCourtesy   from   dbo.Employees  where   EmployeeID   =   5 
select case   @sex 
when   'Ms.'   then   '女士' 
when   'Mr.'   then   '男士' 
else   'nothing' end 

还是：
declare   @sex   nvarchar(50) 
select   @sex   =   TitleOfCourtesy   from   dbo.Employees  where   EmployeeID   =   5 
if(@sex='Ms.') print '女士' 
if(@sex='Mr.') print  '男士' 
else  print   'nothing' 

[sailormars]

select @sex = TitleOfCourtesy from dbo.Employees
where EmployeeID = 5
print @sex
print case @sex
when 'Ms.' then '女士'
when 'Mr.' then '男士'
else 'nothing'
end
我已经明白了,case只能用在表达式中.