Den 2012-04-24 10:39 skrev Thomas Steinmaurer såhär: > > > Den 2012-04-24 10:18 skrev Thomas Steinmaurer såhär: > >> > >>> Is there any way to enforce uniqueness of all non-nulls in a nullable > >>> column? > >> > >>> The "business requirement" would be "this kind of thing has an > optional > >>> attribute, that, if it exists, is unique". For example, a company > may or > >>> may not exist in the Byro van Dijk company database, but if it does > >>> exist it will have a unique BvD id. I'd like to enforce this > uniqueness. > >> > >> I'm sure I don't understand the question properly, because a Firebid > >> UNIQUE constraint on a null-able column doesn't take NULLs into > account, > >> as long as it isn't a compound UNIQUE constraint made up from> 1 > >> columns.. > >> > >> > >> > > > > Oh!? I didn't know. RTFM then... :-) I was working in SQL Server and > > then this cropped up. > > Yeah, welcome in the world writing applications supporting multiple > backends. Little, neat differences along different products. ;-) > > Regards, > Thomas > >
Been doing that since about 1997 actually. Don't know why it didn't occur to me this time. But it wasn't an app - just some ad hoc data work - import data from external source. Kjell -- -------------------------------------- Kjell Rilbe DataDIA AB E-post: [email protected] Telefon: 08-761 06 55 Mobil: 0733-44 24 64 [Non-text portions of this message have been removed] ------------------------------------ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Visit http://www.firebirdsql.org and click the Resources item on the main (top) menu. Try Knowledgebase and FAQ links ! Also search the knowledgebases at http://www.ibphoenix.com ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/firebird-support/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/firebird-support/join (Yahoo! ID required) <*> To change settings via email: [email protected] [email protected] <*> To unsubscribe from this group, send an email to: [email protected] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
