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！

------解决方案--------------------

SQL code

if exists (select 1 from @MySubject where parentid = rtrim(@MyID))
return 1
else
return 0

------解决方案--------------------

SQL code
create PROCEDURE [dbo].[bExistDir] 
(@MySubject varchar(64),
  @MyID int)
AS
BEGIN
    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 0

END