Question

I need to build a query with 4 columns (sql 2005).

Column1: Product
Column2: Units sold
Column3: Growth from previous month (in %)
Column4: Growth from same month last year (in %)

In my table the year and months have custom integer values. For example, the most current month is 146 – but also the table has a year (eg 2011) column and month (eg 7) column.

Is it possible to get this done in one query or do i need to start employing temp tables etc??

Appreciate any help.

thanks,

KS

Answer 1

KS,
To do this on the fly, you could use subqueries.

SELECT product, this_month.units_sold,
    (this_month.sales-last_month.sales)*100/last_month.sales,
    (this_month.sales-last_year.sales)*100/last_year.sales
    FROM (SELECT product, SUM(units_sold) AS units_sold, SUM(sales) AS sales
            FROM product WHERE month = 146 GROUP BY product) AS this_month,
         (SELECT product, SUM(units_sold) AS units_sold, SUM(sales) AS sales
            FROM product WHERE month = 145 GROUP BY product) AS last_month,
         (SELECT product, SUM(units_sold) AS units_sold, SUM(sales) AS sales
            FROM product WHERE month = 134 GROUP BY product) AS this_year
    WHERE this_month.product = last_month.product
      AND this_month.product = last_year.product

If there’s a case where a product was sold in one month but not another month, you will have to do a left join and check for null values, especially if last_month.sales or last_year.sales is 0.