Q6 - A hint?

Question

Hi,

I'm having trouble finding the trick to Q6, I already managed to create a query for summing the profits by months and stores at the same table, but how do I approach the difference between consecutive rows thing? Can we have a small hint?

Thanks,

Matan.

Answer 1

Don't think about consecutive rows, as there are many months missing (so maybe months in consecutive rows are not consecutive).

Instead, think about joining the table you created to itself, in a way that you'll get a row in the joined table for each couple of consecutive months.

(That's, of course, only one of many possible solutions)