From: Rajesh Kumar Mallah. <mallah@trade-india.com>
To: pgsql-sql@postgresql.org
Subject: enforcing with unique indexes..
Date: Sat, 5 Oct 2002 12:19:25 +0530
Message-ID: <200210051219.07553.mallah@trade-india.com> (raw)
Hi ,
can anyone tell me how can i enforce below in a table.
I want that no more that one distinct userid exists for a given group_id
in the table.
ie i want 1 to 1 mapping between group_id and userid so that , there shud not be a
single group_id having more that one kind of userid.
SELECT group_id from eyp_listing group by group_id having count(distinct userid) > 1 ;
always returns empty.
can it be done with some sort of UNIQUE INDEX?
Regds
MAllah.
--
Rajesh Kumar Mallah,
Project Manager (Development)
Infocom Network Limited, New Delhi
phone: +91(11)6152172 (221) (L) ,9811255597 (M)
Visit http://www.trade-india.com ,
India's Leading B2B eMarketplace.
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To: pgsql-sql@postgresql.org
Cc: mallah@trade-india.com
Subject: Re: enforcing with unique indexes..
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