From: | Andreas Kretschmer <andreas(at)a-kretschmer(dot)de> |
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To: | pgsql-novice(at)lists(dot)postgresql(dot)org |
Subject: | Re: Two relations from parent table to child table |
Date: | 2019-01-22 05:43:45 |
Message-ID: | dd0abaca-fa0c-2a08-b7ef-a84e46146033@a-kretschmer.de |
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Lists: | pgsql-novice |
Am 22.01.19 um 02:07 schrieb JORGE MALDONADO:
> Hi,
>
> I have a table of games and a catalog of teams where each game is
> always played by 2 teams. How should I design these tables? Please
> refer to the image below.
>
> I suppose that option #2 is the correct one but I want to make sure it is.
> I have never seen 2 relations from a parent table to a child table.
solution 1 is the correct one.
you have to use 2 joins to select that, and you have to use 2 aliases
for the 2 joins to distinct the team-table. Something like
select ... from ... left join teams t1 on game.team1 = t1.id left join
teams t2 on game.team2=t2.id ...
Andreas
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