Working with my sales/client management system using psql I have a select statement to identify contacts to be made. This statement works:
select (C.contact_id, C.lname, C.fname, C.direct_phone, O.org_name, A.next_contact)
from Contacts as C, Organizations as O, Activities as A where C.org_id = O.org_id and C.contact_id = A.contact_id and A.next_contact <= 'today' and A.next_contact > '2018-12-31' and A.next_contact is not null; but would benefit from tweaking. When I have had multiple contacts with someone I want only the most recent one displayed, not all, and they should be no more ancient than a defined period (e.g., a month). I want to learn how to make this query cleaner and more flexible. When I write the UI for this I want to be able to specify a data range in addition to a fixed 'today'. Pointers on what to read will be very helpful. TIA, Rich