SQL 2005 写了个类型oracle sequence 的存储过程

先建张存序列号的表
CREATE TABLE [dbo].[Sequence](
[SequenceNO] [bigint] NOT NULL,
[date] [datetime] NOT NULL
) ON [PRIMARY]

创建存储过程

CREATE PROCEDURE GetSerialNo
@no int output
AS
begin

if not exists(select 1 from sequence where datediff(dd,date,getdate())=0)
begin
set @no=1
insert sequence values(@no,getdate())
end
else

begin transaction
select @no=max(sequenceNo) +1 from sequence with(xlock,holdLock) where datediff(dd,date,getdate())=0
update sequence set sequenceNo=@no where datediff(dd,date,getdate())=0
if @@error <> 0
begin
raiserror('Error,can not get SerialNo',16,1)
rollback
return
end
commit transaction
end
return @no