comparing rows on a mysql table
- by user311324
Ok here's the deal I got one table with a bunch of client information.
Each client makes up to one purchase a year which is represented by an individual row.
there's a column for the year and there's a column the contains a unique identifier for each client. What I need to do is to construct a query that takes last year and this year and shows me which clients were here made a purchase last year but not make a purchase this year.
I also need to build a query that shows me which clients did not make a purchase last year and the year before last but did make a purchase this year.