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Article #15195Re: MySQL, avanceret distinct? (i hvert fald for mig)
From: Niels Andersen
Date: Sun, 08 Jul 2001 08:09
Date: Sun, 08 Jul 2001 08:09
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"Jonas Delfs" <jonas@nospam.delfs.dk> wrote in message
news:9i74tk$5qc$1@sunsite.dk...
> > Jeg har en tabel hvor n�glen er en streng. Faktisk er det to (i
fremtiden
> > m�ske flere) ord, sammensat med en underscore (_), fx. s�dan her:
> > "key1_key2".
> > Det fungerer ganske glimrende, men det er vist lidt uheldigt
> > database-design. Jeg har nu i hvert fald det problem, at jeg skal have
en
> > liste over f�rste del.
> Pseudokode:
> SELECT DISTINCT SUBSTRING(feltnavn, LOCATE('_', feltnavn), LOCATE('_',
> feltnavn, LOCATE('_', feltnavn))) AS key1 FROM tabel
Jeg skal snart have l�st den manual igennem, der er vist meget guf... :)
Men tak for inspirationen, dette bliver vist l�sningen:
SELECT DISTINCT SUBSTRING_INDEX(felt, '_', 1) AS key1 FROM tabel;
--
Mvh.
Niels Andersen
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X-Google-Language: DANISH,ASCII X-Google-Thread: fcdf9,dbc86c5093ce8294 X-Google-Attributes: gidfcdf9,public X-Google-ArrivalTime: 2001-07-08 01:10:10 PST Path: arc1-ca.pugleaf.net!archiver1.google.com!newsfeed.google.com!sn-xit-02!supernews.com!news.tele.dk!212.54.64.131!news100.image.dk!news000.worldonline.dk.POSTED!not-for-mail From: "Niels Andersen" <niels-usenet@myplace.dk> Newsgroups: dk.edb.database References: <lpo17.5032$c63.500836@news000.worldonline.dk> <9i74tk$5qc$1@sunsite.dk> Subject: Re: MySQL, avanceret distinct? (i hvert fald for mig) Lines: 26 X-Priority: 3 X-MSMail-Priority: Normal X-Newsreader: Microsoft Outlook Express 6.00.2462.0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2462.0000 Message-ID: <xzU17.337$6x5.52992@news000.worldonline.dk> Date: Sun, 8 Jul 2001 10:09:04 +0200 NNTP-Posting-Host: 213.237.14.186 X-Complaints-To: news-abuse@wol.dk X-Trace: news000.worldonline.dk 994579805 213.237.14.186 (Sun, 08 Jul 2001 10:10:05 MET DST) NNTP-Posting-Date: Sun, 08 Jul 2001 10:10:05 MET DST Organization: Customer of Tiscali A/S (World Online)