maria-discuss team mailing list archive

[Roberto Spadim <roberto@xxxxxxxxxxxxx>]

/) this worked nice, since i was only replacing one character =) no problem
now i done the stored function, and executed it with 15 seconds, maybe a
native function could execute it with ~3 seconds

:) thanks guys


2014-03-19 12:44 GMT-03:00 Peter Laursen <peter_laursen@xxxxxxxxxx>:

> @Roberto .. write a Stored Function. You can do that with HeidiSQL (or
> whatever available client). It may be done basically as a loop doing
> something like
>
> * checking for the substring from 1st character - increment count if
> substring is found
> * TRIM the 1st/leftmost character away
> .. and repeat till end of string is reached.
> (I don't claim this will be high performing, and there are probably many
> ways to do it)
>
> But now consider you have the string 'abbbbbbc' and want to count for
> occurrences of 'bb'.  How many will/shall you find? 3 or 5? This is
> somewhat ambigious in this case actually, and only you can decide how such
> function should work to fit your needs.
>
> -- Peter
>
>
>
> On Wed, Mar 19, 2014 at 4:22 PM, Reindl Harald <h.reindl@xxxxxxxxxxxxx>wrote:
>
>>
>>
>> Am 19.03.2014 16:04, schrieb Roberto Spadim:
>>
>> > yes, but i have a table with 1M rows, and i don't have
>> php/c/python/perl here, just heidisql
>> > any help is wellcome
>> >
>> > 2014-03-19 12:03 GMT-03:00 Reindl Harald <h.reindl@xxxxxxxxxxxxx<mailto:
>> h.reindl@xxxxxxxxxxxxx>>:
>>
>> >
>> >     Am 19.03.2014 15:51, schrieb Roberto Spadim:
>> >     > hi guys, i'm not finding a function to return how many character
>> i have, for example:
>> >     >
>> >     > "banana"
>> >     >
>> >     > i want a function that return 2 "n" characters, example:
>> >     > substr_count("banana","n") => 2
>> >     >
>> >     > sorry it a begginners question, but i didn't found it in
>> mysql/mariadb manual
>> >
>> >     that is not the job of the database server because it
>> >     can't use indexes for such things - just iterate
>> >     the result and do it in the application
>>
>> it would be so much easier if
>>
>>  * reply only to the list so the next reply get not off-list
>>  * don't top post
>>  * dont reply in HTML to plaintext posts
>>
>> these are the string functions
>> https://mariadb.com/kb/en/string-functions/
>>
>> * the database would not be faster as a script
>> * frankly the opposite may be true http://bugs.mysql.com/bug.php?id=59253
>> * there is no function like substr_count
>> * just install PHP or whatever
>>
>> there is not much to help
>>
>>
>>
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>
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-- 
Roberto Spadim
SPAEmpresarial
Eng. Automação e Controle