maria-discuss team mailing list archive

[Roberto Spadim <roberto@xxxxxxxxxxxxx>]

ow, really nice :) it solve the problem, thanks sergei!

2016-01-20 10:30 GMT-02:00 Sergei Golubchik <serg@xxxxxxxxxxx>:

> Hi, Roberto!
>
> On Jan 20, Roberto Spadim wrote:
> > Hi guys! There's a "easy/fast" way to rewrite a query from this:
> >
> > Select datetime,key,value from table where ...
> >
> > To this:
> >
> > Select datetime, value1 as key1, value2 as key2, .... From table where
> ...
> >
> > I don't remember the right name in R/python (pandas) language but it's
> > something like vector/matrix merge
> >
> > The ideia is, instead of one line of date key vale, use a single date,
> and
> > "put" values as columns, and the columns name is the key name
> >
> > The table structure is something like:
> > Create table (
> > Datetime datetime not null,
> > Key varchar(255) not null,
> > Value double not null,
> > Primary key(datetime,key)
> > )
> >
> > Any idea is wellcome
> > I know there's many solutions, if i have >100 columns, if datetime is
> > sparse (only one key have values per datetime value), etc etc
>
> Check the PIVOT table type of the CONNECT engine.
> https://mariadb.com/kb/en/mariadb/connect-table-types-pivot-table-type/
>
> Regards,
> Sergei
> Chief Architect MariaDB
> and security@xxxxxxxxxxx
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>
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>
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>



-- 
Roberto Spadim
SPAEmpresarial - Software ERP
Eng. Automação e Controle