maria-discuss team mailing list archive

[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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