一个简单的存储过程优化，谢谢！
create PROCEDURE [dbo].[bExistDir]
(@MySubject varchar(64),
@MyID int)
AS
BEGIN
declare @var1 nvarchar(128)
declare @iNum int;
select @var1 = 'select @a = count(*) from '+@MySubject + 'Dir' + ' where parentid = ' + rtrim(@MyID)
exec sp_executesql @var1,N'@a int output',@iNum output
if @iNum = 0
begin
return 0
end
else
begin
return 1
end
end

因为 if exist 效率应该比 count(*)高，所以想更改一下，但是不知道该如何写，谢谢！

[解决办法]

SQL code

if exists (select 1 from @MySubject where parentid = rtrim(@MyID))return 1elsereturn 0
[解决办法]
SQL code
create PROCEDURE [dbo].[bExistDir] (@MySubject varchar(64),  @MyID int)ASBEGIN    DECLARE @t TABLE(ID int)    INSERT @T EXEC('if exists(select 1 from '+@MySubject + 'Dir' + ' where parentid = ' + @MyID+') select 1 ')    IF EXISTS(SELECT 1 FROM @t)      return 1    ELSE         return 0END