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Regular expression not working [^xyz]

From: Stuart Peters <s(dot)peters(at)surrey(dot)ac(dot)uk>
To: pgsql-bugs(at)postgresql(dot)org
Subject: Regular expression not working [^xyz]
Date: 2000-10-02 17:15:03
Message-ID: v04220809b5fe6b4bafd3@[131.227.9.109] (view raw, whole thread or download thread mbox)
Thread:
Lists: pgsql-bugs
I wasn't aware that Postgres accepted regular expressions (they seem 
undocumented) until reading the draft of Bruce Momjian's forthcoming 
book.  However, now having looked at them, I have found a bug in 
matching a particular expression from a PostgreSQL database.  I am 
using:

  PostgreSQL 7.0.2 on sparc-sun-solaris2.7, compiled by gcc 2.8.1

I have created a very brief table ('bug') that has one 'text' field 
('title')  and three records:


\connect - postgres
CREATE TABLE "bug" (
         "title" text
);
COPY "bug" FROM stdin;
abcdefghijklm
nopqrstuvwxyz
aeiou
\.



The following queries work as expected, EXCEPT for [2].  I believe 
that [2] and [3] should return identical results, but [2] simply 
lists ALL titles:

[1]  select title from bug where title ~* '[ae]';

       Lists titles that contain one of the letters a or e: WORKS

[2]  select title from bug where title ~* '[^ae]';

       Lists ALL titles rather than those that don't contain a or e: 
DOESN'T WORK
       (Note: 'select title from bug where title ~* '[^a];' does not work either

[3]  select title from bug where title !~* '[ae]';

       Lists all titles that don't contain a, q, x or z: WORKS

[4]  select title from bug where title ~* '^[^ae]';

       Lists all titles that do not begin with a, q, x or z: WORKS


I hope this helps with development,

Regards,
Stuart Peters
____________________________________________________________________________
Stuart Peters, Dept of Sociology, University of Surrey, Guildford GU2 7XH,
United Kingdom.  Tel: +44 (0)1483 259292 Fax: +44 (0)1483 259551

Electronic Publishing Resource Service - EPRESS   http://www.epress.ac.uk/

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