用SQL Server HAVING子句计算列和平均值

CREATE FUNCTION [dbo].[AverageSale_fns] 
(
      -- Add the parameters for the function here
      --  
)
RETURNS money

AS
BEGIN
      -- Declare the return variable here
      DECLARE @Result money


      -- Add the T-SQL statements to compute the return value here
      SET @Result =(SELECTAvg(TotalSale)AS AverageSale
      FROM dbo.SalesTotals_fnt())


      -- Return the result of the function
      RETURN @Result


END