Re: implementation of a many-to-many relationship - Mailing list pgsql-sql

From Josh Berkus
Subject Re: implementation of a many-to-many relationship
Date
Msg-id web-811711@davinci.ethosmedia.com
Whole thread Raw
In response to implementation of a many-to-many relationship  (Dalton Shane <se401029@cs.may.ie>)
List pgsql-sql
Dalton,

> I need to implement a many-to-many relationship in PostgreSQL but
>  don't know how 
> to. I've trawled through the mailing lists but can't find anything,
>  it's very 
> easy to do in Access so it can't be that hard in PostgreSQL.

No, it's not hard.  It's very basic, which is why it's not specificallydocumented in the PostgreSQL docs.

> I created a linking table between two tables (voter, candidates)
>  called 
> c_voting, I then reference the two table's primary keys to create a
>  composite 
> primary key for c_voting.

This is correct.

> However when I go to input data into c_voting I get a referential
>  integrity 
> error saying that the primary key of table voter doesn't match
>  primary key of 
> c_voting (which it shouldn't).

Can you please post your exact INSERT statements and error message? From my perusal, the problem is with how you are
insertingthe data,not your table design, which is fine (although I question your needfor the DEFERRABLE & INITIALLY
DEFERREDstatements).
 

-Josh

______AGLIO DATABASE SOLUTIONS___________________________                                      Josh Berkus Complete
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