Question

For the last few days I have been attempting to find a method to pull a very important set of information from a table that contains what I call daily counts. I have a table that is setup as follows.

person|company|prod1|prod2|prod3|gen_date

Each company has more than one person, and each person can have different combinations of products that they have purchased. What I have been trying to figure out is a SQL statement that will list the number of people that have bought a particular product per company. So an output similar to this:

Comp ABC | 13 Prod1 |  3 Prod2 | 5 Prod 3
Comp DEF |  2 Prod1 | 15 Prod2 | 0 Prod 3
Comp HIJ |  0 Prod1 |  0 Prod2 | 7 Prod 3 

Currently if a person did not select a product the value being stored is NULL.

Best I have right now is 3 different statements that can produce this information if run on their own.

SELECT Count(person) as puchases, company 
FROM Sales  WHERE prod1 = '1' and gendate = '3/24/2010' 
Group BY company

Answer 1

SELECT      company,
            SUM(COALESCE(prod1, 0)) AS total_prod1,
            SUM(COALESCE(prod2, 0)) AS total_prod2,
            SUM(COALESCE(prod3, 0)) AS total_prod3
FROM        Sales  
WHERE       gendate = '2010-03-24' 
GROUP BY    company

But you definitely should normalize you table – split it in 4:

• Company,
• Person,
• Product,
• Person_Product_Purchase (with the date of the purchase).