Comments for codejanitor

Comment on Levenshtein Distance as a MySQL Stored Function by Aaron D. Campbell

Aaron D. Campbell — Sun, 28 Jun 2009 14:50:08 +0000

I have a zip code database for the US. When I do a query like this it took almost 30 seconds:

SELECT `zipcode` , `city` , `statecode` , (
( 5 * levenshtein(
‘85326′, LOWER( `zipcode` ) )
)
) AS ld
FROM `zipcode`
HAVING `ld` <50
ORDER BY `ld` , `city`
LIMIT 50

The same query after compiling and installing the UDF from http://joshdrew.com/ took .1 seconds. I don’t know if it’s related to the all number issue mentioned above or if it’s because it’s an 8.7M table with 70k+ rows, but it’s definitely too slow for me to use.

Comment on Levenshtein Distance as a MySQL Stored Function by Morgan

Morgan — Thu, 18 Jun 2009 06:41:41 +0000

Good work. I add this part to check those null values. Thanks

DECLARE cv0, cv1 VARBINARY(256);
SET cv1 = 0×00, j = 1, i = 1, c = 0;
IF s1 IS NULL THEN SET s1_len =0;
ELSE SET s1_len = CHAR_LENGTH(s1);
END IF;
IF s2 IS NULL THEN SET s2_len =0;
ELSE SET s2_len = CHAR_LENGTH(s2);
END IF;

Comment on Levenshtein Distance as a MySQL Stored Function by tom

tom — Thu, 21 May 2009 16:07:57 +0000

@Tobi: thanks for the compile tips. works nice.

but beware that mysql_config argument is minus minus cflags, this blog thing seems to modify the minus minus into some other kind of dash.

Comment on Levenshtein Distance as a MySQL Stored Function by Les

Les — Sun, 22 Feb 2009 07:19:54 +0000

Thanks for the code if works well but I would like to use it with the Damerau option included. Does anyone have a stored procedure available with the Damerau option included?

Comment on Levenshtein Distance as a MySQL Stored Function by Tom

Tom — Thu, 22 Jan 2009 17:23:17 +0000

Thanks for the code; it works fine, no problems so far.
But I wish to use it on a large amount of entries (~30000+), which takes quite some time. I wonder if there’s any possibility to limit the maximum difference to a constant value, e.g. 10, so differences greater than that don’t need to be calculated to reduce computing time.
Would that be possible?

Comment on Levenshtein Distance as a MySQL Stored Function by Steffen

Steffen — Wed, 07 Jan 2009 13:33:58 +0000

I get serious problems when trying to compare strings containing numbers only. MySQL server seems to crash!

query: …LEVENSHTEIN(`POSTALCODE`,’14482′) <= 2…
result: #2006 - MySQL server has gone away

What could be the problem?

Comment on Levenshtein Distance as a MySQL Stored Function by Jason

Jason — Wed, 26 Nov 2008 18:01:48 +0000

Are you changing the delimiter before trying to create the function? You’ll need to do that so that the semicolons in the function don’t mess up creating the function. See here: http://dev.mysql.com/doc/refman/5.0/en/create-procedure.html

Comment on Levenshtein Distance as a MySQL Stored Function by aleza

aleza — Wed, 26 Nov 2008 11:36:41 +0000

PLease anyone? i need this mysql function working and I keep getting sintax errors, i am using WAMP (mysql5.0.51b)

please i need help
I keep getting this error

Error

SQL query:

CREATE FUNCTION LEVENSHTEIN(
s1 VARCHAR( 255 ) ,
s2 VARCHAR( 255 )
) RETURNS INTDETERMINISTIC BEGIN DECLARE s1_len,
s2_len,
i,
j,
c,
c_temp,
cost INT;

MySQL said: Documentation
#1064 - You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ” at line 5

Comment on Levenshtein Distance as a MySQL Stored Function by aleza

aleza — Tue, 25 Nov 2008 16:25:12 +0000

I keep getting sintax errors! I really need this function!

Comment on AJAX, Safari, and Returning an HTTP Error Code by Scott

Scott — Thu, 23 Oct 2008 16:27:31 +0000

Is it weird that I did another google search and ended up on the same page I commented on two years ago? The internet can be a very small place sometimes. Again, I found this to be useful. Thanks.