On 9/16/11, Always Learning <centos at u61.u22.net> wrote: > Data is generally stored once. However because of legal requirements a > customer's invoicing name and address and delivery address will be > copied from the customer file and permanently stored in an invoice's > header record. This means when the customer's record details are > changed, the invoice continues to show the original name and address > data valid at the time of creating that invoice. > > Each table as a unique reference number. > > A simple retrieval illustration ... > > select * from p2 where p2ref = '$p1ref' .... > > select p3surname, p3forename, p3add1, p3add2, p3add3, p3add4 (etc) from > p3 where p3customer = '$e7customer' .... > > select w1note from w1 where w1date = '$s5date' .... This looks rather similar to what I am doing nowadays instead of massive queries with sub-selects. Glad to see I'm not alone in this direction. Hopefully this is a case of great minds think alike than fools seldom differs! :D