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@mariadb.org -- Vote for my Percona Live 2016 talks: https://www.percona.com/live/data-performance-conference-2016/sessions/maria... https://www.percona.com/live/data-performance-conference-2016/sessions/maria...