SQL 参数，传入参数和自己申明参数——异常抛出

ALTER PROCEDURE [dbo].[OA_RemoveProject]
@Password nvarchar(30), --这是传入的参数
@ProjectNo nvarchar(8)
AS
DECLARE @ProjectId int  --这是声明的参数。
DECLARE @Count int
 
BEGIN
  IF UPPER(@Password)='FEIFEIDEMAO'
    BEGIN
	  SET @Count=(SELECT COUNT(*) FROM DwProject WHERE ProjectNo=@ProjectNo)
	  if @Count=1
		BEGIN
			SET @ProjectId=(SELECT Id FROM DwProject WHERE ProjectNo=@ProjectNo)
			Delete From DwProject Where Id=@ProjectId
			Delete From DwTask Where LinkId=@ProjectId
			Delete From DwProjectRelatedPersonnel Where ProjectId=@ProjectId
			Delete From DwProjectQuestion Where ProjectId=@ProjectId
			Delete From DwProjectFile Where ProjectId=@ProjectId
		END
	  ELSE IF @Count>1
		RAISERROR(N'项目编码对应多个主键ID,无法删除！',11,5)WITH NOWAIT
	  ELSE RAISERROR(N'未找到项目编号！',11,5)WITH NOWAIT
    END
    ELSE
    RAISERROR(N'密码错误，重新执行！',11,5)WITH NOWAIT
END

　　

需求：ID主键，非查询不可取到。但是ProjectNo可以看到。实现通过ProjectNo删除数据，以及关联表数据。（参数是   密码和要删除的项目编号）