如何在MDX中实现递归求和？

CREATE FUNCTION RecursiveSum(@Member [Dimension].[Hierarchy].[Member])
RETURNS Integer
AS
BEGIN
   DECLARE @Sum Integer;
   SET @Sum = @Member.MemberValue;
   
   WITH RECURSIVE FunctionSum AS (
      SELECT @Member AS CurrentMember
      
      UNION ALL
      
      SELECT [Dimension].[Hierarchy].ParentMember AS CurrentMember
      FROM FunctionSum
      WHERE [Dimension].[Hierarchy].ParentMember IS NOT NULL
   )
   
   SELECT @Sum = @Sum + [Dimension].[Hierarchy].MemberValue
   FROM FunctionSum
   
   RETURN @Sum;
END;

WITH MEMBER [Measures].[RecursiveSum] AS RecursiveSum([Dimension].[Hierarchy].[Member])
SELECT [Measures].[RecursiveSum] ON 0
FROM [Cube]