I have a students table and a payments table.
they can be joined by sid
I need to see sids
that have no entry for april. I tried this query, but it shows two students that have an entry for april.
SELECT students.sid, students.name, students.last_name FROM students LEFT JOIN payments ON students.sid = payments.sid WHERE students.Active = 'Yes' AND payments.forMonth != "Apr" GROUP BY payments.forMonth
oddly, other students have also paid for april, but they don't show up in the list.
any help would be greatly appreciated.