Question

SQL Server 2000

I have a table which lists out the months where a particular product can be sold.

ProductCode     MonthNum    MonthName
XXX             1           January
XXX             2           February
YYY             1           January
YYY             3           March
YYY             5           May
ZZZ             6           June
ZZZ             7           July

I need to construct a query that would allow me to pass some parameters:

ProductCode
LatestMonthNum
LatestYear
FutureForecast

that would allow me to construct a set of data list with the total rows based on the number of FutureForecast value and the rows’ value would be beyond the passed LatestMonthNum and LatestYear parameter values.

For example, if I pass the following values to the query:

ProductCode         YYY
LatestMonthNum      5
LatestYear          2012
FutureForecast      5

I would have the data as follows:

ProductCode     MonthNum    Year
YYY             1           2013
YYY             3           2013
YYY             5           2013
YYY             1           2014
YYY             3           2014

Answer 1

I would create a table of months and years in the future (something like a numbers table):

CREATE TABLE future (month int, year int);
DECLARE @m int;
SET @m = 1;
DECLARE @y int;
SET @y = 2000;
WHILE (@y < 2200) -- will my brain be in a jar by now?
  BEGIN
  WHILE (@m < 13)
    BEGIN
    INSERT INTO future (month, year) VALUES (@m, @y);
    SET @m += 1;
    END
  SET @m = 1;
  SET @y += 1;
  END;

Then you can join your products table with the future!

SELECT TOP @FutureForecast
  p.ProductCode, p.MonthNum, f.[year]
FROM Products AS p
JOIN future AS f ON f.[month] = p.MonthNum
WHERE 
  p.ProductCode = @ProductCode
  AND (p.MonthNum > @LatestMonthNum OR f.[year] > @LatestYear)
ORDER BY f.[year], p.MonthNum