如何获取返回值？

[smartyyp]

declare @str as varchar(8000)
declare @returnValue as integer
set @str='select count(id) from table'
set @str=@str+'where ...'
set @str=@str+'and ...'
set @returnValue=exec(@str)
如何用@returnValue获取exec执行sql中的返回字段值count(id)
我上面的方法是错误的，请高手指点!

[pengdali]

declare @str nvarchar(4000)
declare @returnValue as integer
set @str='select @a=count(id) from table'
set @str=@str+'where ...'
set @str=@str+'and ...'

exec sp_executesql @str,N'@a int output',@returnValue output

select @returnValue 结果

[yujohny]

来晚了，up

[Wally_wu]

declare @str as varchar(8000)
declare @returnValue as integer output
set @str='select count(id) from table'
set @str=@str+'where ...'
set @str=@str+'and ...'
set @returnValue=exec(@str)



declare @countid int
exec sp_executesql @countid output