Re: Antw: many-many mapping between unique tables - Mailing list pgsql-sql

From Indraneel Majumdar
Subject Re: Antw: many-many mapping between unique tables
Date
Msg-id Pine.SGI.3.96.1001016130435.121309C-100000@www.cdfd.org.in
Whole thread Raw
In response to Antw: many-many mapping between unique tables  ("Gerhard Dieringer" <DieringG@eba-haus.de>)
Responses JDBC Performance
List pgsql-sql
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

On Mon, 16 Oct 2000, Gerhard Dieringer wrote:

> I'm not sure if I understand your question. Is it right, that the x(i) are different values
> of an column x in table T1 and the y(i) are different values of an column y in table T2?
> And you want to have a n:m relation between the two tables?
> 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).
> 
> I hope this helps.
> 
> 
> Gerhard

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