Let me step back a bit, as I realize upon further reflection that the first method will not work.
As far as the issue about two “Ted” records, read it as though I said two “Ted D” records. It refers to two records in the same table with the same key value. If “Ted D” appeared twice in table 1 and twice in table 2, the join would give four resulting records (all combinations of the records from table 1 and the records from table 2 (and the records from table 3) — that’s fundamentally how a join works. If you don’t want that, then make sure that there are no duplicates within each of the tables. > On Sep 3, 2019, at 9:35 AM, TedJones <t...@mentra.co.uk> wrote: > > Hi Jack > > I'm not sure if I understand your comment about two 'Ted' fields and > duplication of rows. In the example below there is 'Ted' twice in Table3 1 > and 3 and must appear twice as I've shown in the result as the data in the > rest of the row is different. I agree with no duplication of rows if all of > the row is the same. > > Ted > > Table: 1 > Author Title Sales Publication Date > Jim A aa I > Ted B bb J > Dave C cc K > Ted D dd L > > Table: 2 > Author Publisher > Jim him > Ted me > Dave me > Will you > Gary him > > Table:3 > Author Title Country > Ted B UK > Ted D US > Jim A UK > Dave C UK > > Combined table: Result > Author Title Publication Date Publisher Sales Country > Ted B J me bb UK > Ted D L me dd US > Jim A I him aa UK > Dave C K me cc UK > Gary null null him null null > Will null null you null null > > > > > -- > Sent from: > https://www.postgresql-archive.org/PostgreSQL-pgadmin-support-f2191615.html > >
