Question

I am joining 2 tables using Cartesian Product as follows.

select p.type, i.amount 
FROM products p, invoice i
where (p.account = i.id); -- column headers cant be changed despite having same info

This of course displays 2 columns with the respective values.

However I then want to manipulate the data further using COUNT/GROUP BY and SUM/GROUP BY but have been unable to find any relevant examples which I could get to work using 2 tables. (doing them all separately is ok, just getting them to work together is the problem).

For the end result, I want to show 3 columns showing a grouping of the 4 types, with the count of the entries falling under each type, and the total amount/SUM for each type, eg.

Type – Count of Types – Total Value

A – 5 – 500

B – 6 – 1000

C – 1 – 50

D – 2 – 100

Answer 1

Did you try this?

select p.type, count(p.type) Cnt, sum(i.amoumt) Total
FROM products p, invoice i
where (p.account = i.id)
group by p.type