Date: Wed, 16 Oct 2019 11:36:36 +0000 (UTC)
From: Karen Goh <karenworld@yahoo.com>
To: pgsql-sql@lists.postgresql.org
Message-ID: <1846839195.1533405.1571225796919@mail.yahoo.com>
Subject: Should I add a Index Key in this case ?
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Hi Experts,

I have a use case as follows : 

 add constraints to the database so that no two reservations for the same viewing may refer to the same seat.

So, say I have a primary key like this in the table A:


    SEAT_id integer NOT NULL GENERATED ALWAYS AS IDENTITY ( INCREMENT 1 START 1 MINVALUE 1 MAXVALUE 2147483647 CACHE 1 ),
    CONSTRAINT A_pkey PRIMARY KEY (SEAT_id))
WITH (
    OIDS = FALSE
)
TABLESPACE pg_default;

So, basically I would like to create a SEAT_Viewing_Id.

In this case, do I create a Index Key or ?

How should I construct or rather alter my table A to accomodate this SEAT_Viewing_Id ?

Hope someone can tell me how.

Furthermore, whenever an insertion is done via WebApp, I would have to insert the Index key as well or does PostgreSQL will have a way to increment the Index key which is the SEAT_Viewing_Id at the same time?

Thanks & regards,
Karen