Tech-Recipes - Latest Comments in Use regular expressions in MySQL SELECT statements

Re: Use regular expressions in MySQL SELECT statements

Asdfasd — Sat, 06 Aug 2011 10:40:32 -0000

I think you use the ^ character to negate stuff:
[^a-z]
would find anything that wasn't a to z.

Re: Use regular expressions in MySQL SELECT statements

Hallo — Sat, 04 Jun 2011 01:01:49 -0000

sepp du bist der depp

Re: Use regular expressions in MySQL SELECT statements

Gasr — Tue, 26 Apr 2011 05:46:30 -0000

sepp

Re: Use regular expressions in MySQL SELECT statements

Andy Mason — Tue, 05 Apr 2011 12:23:46 -0000

Could also use the '+' operator to match one or more o's ...

select "hellooo" REGEXP "^h[el]+o+$"

Re: Use regular expressions in MySQL SELECT statements

Josef Schalk — Wed, 09 Mar 2011 05:25:56 -0000

was geht denn mitr dir

Re: Use regular expressions in MySQL SELECT statements

Jo — Wed, 09 Mar 2011 05:24:34 -0000

moang

Re: Use regular expressions in MySQL SELECT statements

viji — Wed, 23 Feb 2011 04:00:46 -0000

Re: Use regular expressions in MySQL SELECT statements

Ojio — Sun, 20 Feb 2011 06:47:48 -0000

ach sepp

Re: Use regular expressions in MySQL SELECT statements

Nikn — Sun, 20 Feb 2011 06:21:52 -0000

vwpanzersepp

Re: Use regular expressions in MySQL SELECT statements

Sepp-seppelin_constructions — Sat, 19 Feb 2011 12:30:12 -0000

like und dann %
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Re: Use regular expressions in MySQL SELECT statements

Gas — Sat, 19 Feb 2011 12:25:33 -0000

sepp du depp

Re: Use regular expressions in MySQL SELECT statements

GHead — Wed, 29 Sep 2010 18:36:27 -0000

How to select from a column that not have character? like in php !preg_match('/[a-z]/i')

Re: Use regular expressions in MySQL SELECT statements

Gumuruh S — Thu, 05 Aug 2010 06:17:25 -0000

whoooooo... that's cool!

so anywa, how about we just want to select N until M row only?

Re: Use regular expressions in MySQL SELECT statements

gilahacker — Fri, 08 Jan 2010 13:29:27 -0000

@Wayne

I ran the following queries three times each on my MySQL database which has over 200,000 articles in it:

SELECT * FROM `mos_content` WHERE title REGEXP 'article';
SELECT * FROM `mos_content` WHERE title LIKE '%article%';

REGEXP averaged 0.047333333 seconds
LIKE averaged 0.035333333 seconds

There was hardly any deviation between the runs. But it's obvious that LIKE is about 25% faster than REGEXP for some reason (at least on my specific MySQL configuration).

Re: Use regular expressions in MySQL SELECT statements

Wayne — Thu, 07 Jan 2010 13:33:40 -0000

I've been using mySQL for years, and I've been using regular expressions for years. Yet, somehow, I never found out until just now (from this recipe) that mySQL supported them in a manner like this. That's amazingly useful. Thank you!

(Of course, I also see that you wrote this recipe almost six years ago - so thank you for six years ago!) :)

Does REGEXP have a bigger or smaller or identical performance hit when compared to using LIKE for substrings?

For instance, here's a couple pairs of otherwise equivalent queries. Within each pair, which would be better for performance?
SELECT * FROM events WHERE id REGEXP 'abcd'
SELECT * FROM events WHERE id like '%abcd%'

SELECT * FROM events WHERE id REGEXP 'abcd.*lmnop'
SELECT * FROM events WHERE id like '%abcd%lmnop%'

Is LIKE just a specialize synonym for REGEXP which actually uses REGEXP in the background, or is it truly it's own function? (Asked because if it uses REGEXP, then the performance hits should be identical within both those pairs.)

Anyway, thanks again for adding a weapon to my arsenal that should have been there years ago. I can't imagine how I've overlooked it for so long.

Re: Use regular expressions in MySQL SELECT statements

Shane — Fri, 11 Dec 2009 12:58:04 -0000

santoshb,

i don't know if you have the answer to your question yet, but your regexp is only look for one 'o'. The $ sign means the absolute end of the string.

You could either do:

^h[el]+o

or..

^h[el]+ooo$

Re: Use regular expressions in MySQL SELECT statements

santoshb — Fri, 13 Nov 2009 00:33:21 -0000

may i know Why this query showing false result

select "hellooo" REGEXP "^h[el]+o$";

Re: Use regular expressions in MySQL SELECT statements

////AE — Tue, 07 Jul 2009 14:05:57 -0000

Is there a way to use regexp when defining a table to SELECT $something from?

Re: Use regular expressions in MySQL SELECT statements

Lawrence — Sun, 15 Mar 2009 18:56:54 -0000

Thank you