From: | "Gerhard Dieringer" <DieringG(at)eba-haus(dot)de> |
---|---|
To: | <indraneel(at)www(dot)cdfd(dot)org(dot)in> |
Cc: | <pgsql-sql(at)postgresql(dot)org> |
Subject: | Re: Antw: many-many mapping between unique tables |
Date: | 2000-10-16 08:09:50 |
Message-ID: | s9ead40a.069@kopo001 |
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Thread: | |
Lists: | pgsql-sql |
>>> Indraneel Majumdar <indraneel(at)www(dot)cdfd(dot)org(dot)in> 16.10.2000 22.13 Uhr >>>
> Yeah you understand the problem perfectly. The third table will definitely
> contain unique entries if you take both x and y simultaneously. I wanted
> some way of mapping where I would not need to repeat individual values of
> x and y. I am not from a maths background and have absolutely no idea of
> database design.
>
> Is it possible to map the columns without repeating values?
>
> \Indraneel
I don't know what type of data your columns x and y contain. If they are,
for example, of type text and contain long strings, then it would be better
to add an integer id column in each tables T1 and T2: x_id and y_id and
use these ids in the table T12.
Then you only have to repeat the (short) numeric vales in T12. But I think there
is no way to totaly avoid any repetition.
--------------
Gerhard
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