From: Aaron Bono <postgresql@aranya.com>
To: Postgres SQL language list <pgsql-sql@postgresql.org>
Subject: Regular Expression in SQL
Date: Sat, 15 Jul 2006 17:03:23 -0500
Message-ID: <bf05e51c0607151503j53fffb01y38840a72c43a50f6@mail.gmail.com> (raw)
I recall not long ago a discussion about regular expressions in a query that
hit on this exact topic but don't think it was ever resolved so I am giving
it a go again...
Here is my query (keep in mind that I am just experimenting now so don't
worry about the fact that I am using nested substring function calls):
SELECT
referrer,
substring(referrer FROM '^([^\\/]*\\/\\/[^\\/]*)(\\/)?'),
substring(referrer FROM
'^[^\\/]*\\/\\/www\\.google\\.[^\\/]*\\/[^\\?]*\\?(.*)$'),
substring(substring(referrer FROM
'^[^\\/]*\\/\\/www\\.google\\.[^\\/]*\\/[^\\?]*\\?(.*)$') FROM
'((%&q=)|(q=))#"[^&]*#"((&%)|())' FOR '#')
FROM one_hour_air.web_page_view
WHERE referrer ~ '^[^\\/]*\\/\\/(www.google\\.[^\\/]*)\\/'
What I get is:
referrer
substring
substring_1
substring_2
http://www.google.ca/search?q=one+hour+heating&hl=enhttp://www.google.ca
q=one+hour+heating&hl=en
q=
http://www.google.com/search?hl=en&q=One+hour+heating+and+Airhttp://www.google.com
hl=en&q=One+hour+heating+and+Air
hl=en&q=
What I expected for substring_2 was (respectively):
one+hour+heating
One+hour+heating+and+Air
I thought by using the FOR '#' I could specify exactly what part of the
expression I would get but it still grabs the first (...) of the pattern.
At least that is what the documentation in seciton 9.7.2 at
http://www.postgresql.org/docs/8.1/static/functions-matching.html led me to
believe. How can I get the part of the string I am really after without
using one nested substring after another?
Thanks,
Aaron Bono
==================================================================
Aaron Bono
Aranya Software Technologies, Inc.
http://www.aranya.com
==================================================================
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To: pgsql-sql@postgresql.org
Cc: postgresql@aranya.com
Subject: Re: Regular Expression in SQL
In-Reply-To: <bf05e51c0607151503j53fffb01y38840a72c43a50f6@mail.gmail.com>
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