2014-03-19 12:25 GMT-03:00 Peter Laursen <[email protected]>: > I feel like to comment here on "because it can't use indexes for such > things". This is not a serious reply IMO. It is just another way or saying > "Please shut up!" >
yes > > How many existing string functions ( > http://dev.mysql.com/doc/refman/5.6/en/string-functions.html) use an > index? Does "select concat('a','b');" do for instance? I cannot think of > any. And why do we have 'stored programs' if a database server should only > do things that uses indexes? Does a WHILE-loop inside a stroed program use > an index? > > Unlike most other RDBMS, MySQL has a tradition to do things in the > application thet other RDBMS would do in the database. But that traditions > is/was because of lack of functionality in the server before 5.0 (what is > still the case in some respects. Try compare a MySQL TRIGGER with an > Oracle or SQL Server same, for instance). > > That said: this functionality can be implemented in a stored function > using existing string functions (or in the application, as sugggested) > quite easily. It is not possible (or desirable) to add build-in functions > for everything. And I have no clue is such string function exists in other > RDBMS. > if i have gcc and mariadb source here i could create a native function, that`s very fast, but i have only heidisql :) thanks for the idea of replace and difference, that worked very nice =) i don`t know why, but many functions (of php for example) could be implemented easily, but why not implement it? there`s a sql 2000 standard or something like it to disallow this kind of functions? maybe we could create a plugin with many function native to mariadb, and set it on/off to allow a mysql compatibility > > > -- Peter > -- Webyog > > > On Wed, Mar 19, 2014 at 4:03 PM, Reindl Harald <[email protected]>wrote: > >> >> >> 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 >> >> >> _______________________________________________ >> Mailing list: https://launchpad.net/~maria-discuss >> Post to : [email protected] >> Unsubscribe : https://launchpad.net/~maria-discuss >> More help : https://help.launchpad.net/ListHelp >> >> > > _______________________________________________ > Mailing list: https://launchpad.net/~maria-discuss > Post to : [email protected] > Unsubscribe : https://launchpad.net/~maria-discuss > More help : https://help.launchpad.net/ListHelp > > -- Roberto Spadim SPAEmpresarial Eng. Automação e Controle
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