LISTING 2: Solution 1, First Step: View That Returns Each Month’s Trend
USE tempdb
GO

CREATE VIEW VTrends
AS

SELECT
  smonth,
  SIGN(qty-
      (SELECT qty
   FROM Sales
   WHERE smonth = 
           (SELECT MAX(smonth)
            FROM Sales AS S2
            WHERE S2.smonth < S1.smonth))) AS trend
FROM Sales AS S1
GO<None>