Re: joining tables

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
thesame table with the same key value. If “Ted D” appeared twice in table 1 and twice in table 2, the join would give
fourresulting records (all combinations of the records from table 1 and the records from table 2 (and the records from
table3) — that’s fundamentally how a join works. If you don’t want that, then make sure that there are no duplicates
withineach of the tables. 

> On Sep 3, 2019, at 9:35 AM, TedJones <ted@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
>
>