| List: | General Discussion | « Previous MessageNext Message » | |
| From: | Paul DuBois | Date: | July 6 2001 10:49pm |
| Subject: | Re: Perhaps a stupid question about KEY... | ||
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At 12:14 AM +0200 7/7/01, Fournier Jocelyn [Presence-PC] wrote: >Hi, > >Is there any structural difference between a PRIMARY KEY and a UNIQUE key ? > >Thanks ;) > >Jocelyn Fournier >Presence-PC >www.presence-pc.com They're mostly the same, with these differences: There can only be one PRIMARY KEY per table, whereas you can have multiple UNIQUE keys. Any columns in a PRIMARY KEY must be declared NOT NULL; UNIQUE keys do not have this restriction. -- Paul DuBois, paul@stripped
| Thread | ||
|---|---|---|
| • Perhaps a stupid question about KEY... | Fournier Jocelyn [Presence-PC] | 7 Jul |
| • Re: Perhaps a stupid question about KEY... | Paul DuBois | 7 Jul |
| • Re: Perhaps a stupid question about KEY... | Ken Sommers | 7 Jul |
| • Re: Perhaps a stupid question about KEY... | Jeremy Zawodny | 7 Jul |
| • Re: Perhaps a stupid question about KEY... | Tonu Samuel | 8 Jul |
