Re: enforcing with unique indexes..
От | Rajesh Kumar Mallah. |
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Тема | Re: enforcing with unique indexes.. |
Дата | |
Msg-id | 200210051248.10550.mallah@trade-india.com обсуждение исходный текст |
Ответ на | enforcing with unique indexes.. ("Rajesh Kumar Mallah." <mallah@trade-india.com>) |
Список | pgsql-sql |
Sorry Bhuvan it wont work, COMPOSITE UNIQUE INDEX will prevent entry of rows like (group_id,user_id) 1 1 1 1 what i want to prevent is this: 1 1 1 2 did you notice the distinct inside the count? regds mallah. On Saturday 05 October 2002 12:36, Bhuvan A wrote: > > 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? > > Yes it can be done using UNIQUE INDEX. Create a composite unique index on > these 2 fields and it will do the rest. For more details, try > > $ \h CREATE INDEX > > regards, > bhuvaneswaran -- 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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