Can you have a WITH statement in a tabular user defined function

Question

I have the following code for a UDF but it errors with the message:

Msg 156, Level 15, State 1, Procedure CalendarTable, Line 39 Incorrect syntax near the keyword 'OPTION'.

is it because of my WITH statement as I can run the same code fine in a stored procedure?

SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
-- =============================================
-- Author:   Anthony Main
-- Create date: 18/11/08
-- Description: Produce Table of Dates for Month
-- =============================================
CREATE FUNCTION CalendarTable
(   
    @StartDate DATETIME,
    @EndDate DATETIME
)
RETURNS TABLE 
AS
RETURN 
(
    with    MyCalendar as
      (
      select  cast(@StartDate as datetime) DateValue
      union   all
      select  DateValue + 1
      from    MyCalendar   
      where   DateValue + 1 <= @EndDate
      )

    select  DateValue
    ,       datepart(dy, DateValue) [day of year]
    ,       datename(dw, DateValue) [day]
    ,       datepart(dw, DateValue-1) [day of week]
    ,       datepart(dd, DateValue) [day of month]
    ,       datepart(ww, DateValue) [week]
    ,       datepart(mm, DateValue) [month]
    ,       datename(mm, DateValue) [month]
    ,       datepart(qq, DateValue) [quarter]
    ,       datepart(yy, DateValue) [year]
    ,       datepart(HH, DateValue) [HOUR]
    ,       datepart(MI, DateValue) [MIN]
    ,       datepart(SS, DateValue) [SEC]
    ,       datepart(MS, DateValue) [MILLISECOND]
    from    MyCalendar
    OPTION  (MAXRECURSION 0)
)
GO

Answer 1

Are you missing a closing bracket here? (the closing bracket for "AS RETURN ("

Answer 2

From what I can tell, OPTION MAXRECURSION is not allowed in a UDF. There is an item at connect.microsoft.com with the issue.

Answer 3

No, you can't use the OPTION keyword.

From the documentation: "MAXRECURSION can be used to prevent a poorly formed recursive CTE from entering into an infinite loop. The following example intentionally creates an infinite loop and uses the MAXRECURSION hint to limit the number of recursion levels to two."

If you explain what you want to query (what do you want the end results to look like), we could write a better SQL statement that doesn't need recursion.

Answer 4

You can't use the OPTION in the UDF. Also, since UDFs are usually called in high volume, it probably makes more sense to generate your date range by using a Numbers table (you throw a few thousand numbers in a table - from 1 to 1,000,000, say) and generate your date range table in the UDF from that.

Here's a link to a good set of techniques which use such a utility table - often called a Numbers table or a Pivot table.