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* Re: DDL issue
@ 2024-09-12 23:32 David G. Johnston <[email protected]>
0 siblings, 1 reply; 2+ messages in thread
From: David G. Johnston @ 2024-09-12 23:32 UTC (permalink / raw)
To: Rich Shepard <[email protected]>; +Cc: pgsql-general
On Thursday, September 12, 2024, Rich Shepard <[email protected]>
wrote:
> I have one name in the people table who owns 5 different dairies with three
> different phone numbers, but all 5 have the the same email address.
>
> The five dairies each has its own name and location while the people table
> has five rows with the same last and first names and email address.
>
> Is there a way to have only one entry for the owner in the people table
> while related to five different company names? In some industries, such as
> dairy farms, this is not an unusual situation.
>
Read up on “many-to-many” data models. In SQL they involve a linking
table, one row per bidirectional edge, in addition to the two node tables.
David J.
^ permalink raw reply [nested|flat] 2+ messages in thread
* Re: DDL issue
@ 2024-09-13 12:36 Rich Shepard <[email protected]>
parent: David G. Johnston <[email protected]>
0 siblings, 0 replies; 2+ messages in thread
From: Rich Shepard @ 2024-09-13 12:36 UTC (permalink / raw)
To: pgsql-general
On Thu, 12 Sep 2024, David G. Johnston wrote:
> Read up on “many-to-many” data models. In SQL they involve a linking
> table, one row per bidirectional edge, in addition to the two node tables.
David,
Thanks very much. I knew about those a long time ago but haven't needed them
in a long time so I forgot about them. Will re-learn.
Much appreciated,
Rich
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2024-09-12 23:32 Re: DDL issue David G. Johnston <[email protected]>
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