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]
Views: Raw Message | Whole Thread | Download mbox | Resend email
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/

Responses

Browse pgsql-bugs by date

  From Date Subject
Next Message Bruce Momjian 2000-10-02 17:32:54 Re: grant/revoke bug with delete/update
Previous Message Peter Eisentraut 2000-10-01 20:49:51 Re: grant/revoke bug with delete/update