问题：如何从以下工作代码制作 UDF。
declare @currentweek as date
declare @1stweek as date
declare @2ndweek as date
declare @3rdweek as date
declare @4thweek as date
declare @5thweek as date
set @currentweek= dateadd(dd,0,(dateadd(DD,1-datepart(DW,GETDATE()),getdate())))
set @1stweek= dateadd(dd,7,(dateadd(DD,1-datepart(DW,GETDATE()),getdate())))
set @2ndweek= dateadd(dd,14,(dateadd(DD,1-datepart(DW,GETDATE()),getdate())))
set @3rdweek= dateadd(dd,21,(dateadd(DD,1-datepart(DW,GETDATE()),getdate())))
set @4thweek= dateadd(dd,28,(dateadd(DD,1-datepart(DW,GETDATE()),getdate())))
set @5thweek= dateadd(dd,35,(dateadd(DD,1-datepart(DW,GETDATE()),getdate())))
select
case
when ([1] >= @currentweek and [1]<@1stweek)and ([2] >= @currentweek and [2]<@1stweek) and ([3] >= @currentweek and [3]<@1stweek)then 'RAP'
when ([2] >= @currentweek and [2]<@1stweek)and ([3] >= @currentweek and [3]<@1stweek) then 'RA'
when ([1] >= @currentweek and [1]<@1stweek)and ([3] >= @currentweek and [3]<@1stweek) then 'AP'
when [3] >= @currentweek and [3]<@1stweek then 'A'
when ([1] >= @currentweek and [1]<@1stweek)and ([2] >= @currentweek and [2]<@1stweek) then 'RP'
when [2] >= @currentweek and [2]<@1stweek then 'R'
when [1] >= @currentweek and [1]<@1stweek then 'P'
else null
end as [current week]
,case
when ([1] >= @1stweek and [1]<@2ndweek)and ([2] >= @1stweek and [2]<@2ndweek) and ([3] >= @1stweek and [3]<@2ndweek)then 'RAP'
when ([2] >= @1stweek and [2]<@2ndweek)and ([3] >= @1stweek and [3]<@2ndweek) then 'RA'
when ([1] >= @1stweek and [1]<@2ndweek)and ([3] >= @1stweek and [3]<@2ndweek) then 'AP'
when [3] >= @1stweek and [3]<@2ndweek then 'A'
when (([1] >= @1stweek and [1]<@2ndweek)and ([2] >= @1stweek and [2]<@2ndweek)) then 'RP'
when [2] >=@1stweek and [2] < @2ndweek then 'R'
when [1] >=@1stweek and [1] < @2ndweek then 'P'
else null
end as [Next week Week]
我试图研究CREATE Function命令：
我想出了
CREATE FUNCTION testudf()
returns table
as
begin
Inserted the code
End
Go
然而这并没有奏效。有任何想法吗？
编辑：在退货旁边添加了单词表。
消息 102，级别 15，状态 31，过程 RollingDateRAP，第 81 行“开始
”附近的语法不正确。