RE: Use of regular expression

Dennis,

Thanks for clarifying the regular expression. As usual, I have overcomplicated it.

Rick

-----Original Message-----
From: rpg400-l-bounces@xxxxxxxxxxxx [mailto:rpg400-l-bounces@xxxxxxxxxxxx] On Behalf Of Dennis Lovelady
Sent: Friday, July 16, 2010 6:31 PM
To: 'RPG programming on the IBM i / System i'
Subject: RE: Use of regular expression

Hi, Rick:

To search for the word rick anywhere with a string, your exact regular expression would be (are you ready for this complexity?) 'rick'. That will find the string 'rick' anywhere within the search field.

This is exactly the same as your r{1}i{1}... syntax, and _so_ much more legible. While the SQL suggestion is an option, it is likely to add to your run time. But (like all performance topics) it depends on what else is happening in your code.

Dennis Lovelady
http://www.linkedin.com/in/dennislovelady
--
"I'd like to thank my parents and my mother and father."
-- golfer Greg Norman, accepting an award

I'm wondering if using regular expressions is a good way to handle a
word search. What I need is an exact match of a series of characters,
say 'rick', in a character field. I have only used regular
expressions a couple of times and the syntax still gets me confused.
I think I see a way to do this with with something like r{1}i{1}c{1}k{1}.

I know I can do this with the %SCAN op code. The reason I'm thinking
about using regular expressions is the search will be over a table of
close to 1 billion records and I'm looking for efficiencies any place
I can find them. If an expression can be created I want to do some
comparisons between using a regular expression and %SCAN to see which
is really the best performer.

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