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From: Josh Berkus <josh@agliodbs.com>
Reply-To: josh@agliodbs.com
Organization: Aglio Database Solutions
To: "Moonstruck" <bogus.email@pls-relpy-to.group>,
	pgsql-sql@postgresql.org
Subject: Re: Reverse pattern match.
Date: Mon, 18 Aug 2003 16:11:27 -0700
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Moonstruck,

> I want to create a table of  regular expression patterns (for assessing
> phone numbers), something like:
> CREATE TABLE CallType ( pattern varchar primary key,
>                         type    varchar,
>                         rate    int4);
> INSERT INTO CallType VALUES ('0[3-9]________','Interstate Call',50);
> INSERT INTO CallType VALUES ('9_______','Local Call',25);
> INSERT INTO CallType VALUES ('0011__________%','International Call',100);

PostgreSQL supports real Regular Expressions, via the ~ operator.   See "~"=
=20
under "functions and operators", and then consult your favorite book or=20
online ressouce on how to compose regexps.=20

An example of "is not in 415 area code" would be
phone_no ~ '^415\d{7}'=20
which should be "415" at the beginning followed by at least 7 other digits.

(Folks, please correct my regex code if it's bad!)

The disadvantage to this approach is that it cannot be indexed.=20=20

--=20
-Josh Berkus
 Aglio Database Solutions
 San Francisco