I have two tables:
clients containing clientid, forename, surname
advice containing adviceid, date, clientid
A client could come any number of times for advice.
I want to extract:
the number of clients who have received advice between two dates - date1 and date2 (I can do this)
the number of people who are ‘new’ i.e. the ones who last received advice 12 months or more before date1