Re: Antw: many-many mapping between unique tables

From: KuroiNeko <evpopkov(at)carrier(dot)kiev(dot)ua>
To: pgsql-sql(at)postgresql(dot)org
Subject: Re: Antw: many-many mapping between unique tables
Date: 2000-10-16 15:14:27
Message-ID: 39EB1B53.nail1L21P304T@ed.ed
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> > I am facing a problem in mapping between two tables containing unique
> > entries
> >
> Then you need a third table T12 with columns x and y, that contains one
> row for each
> mapping of a x(i) with a y(j).

That's it. Normalize it. Relation T12 may also require the third field,
`direction', to specify whether this is T1 -> T2 or T2 -> T1. In general,
it'd be much better to re-design data layout.

--

Well I tried to be meek
And I have tried to be mild
But I spat like a woman
And I sulked like a child
I have lived behind the walls
That have made me alone
Striven for peace
Which I never have known

Dire Straits, Brothers In Arms, The Man's Too Strong (Knopfler)

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