CSV select some columns but not all

[SebastiendOrnano]

I try to find a way to download a csv file but only on chosen columns.

I prepared a form to select the columns. I tried to use directly the variables in a select query inside the cvs component until I understood that in sqlite it is not possible to use variables in a query (I am still an early learner in sql !). The only way is to introduce some python function but I want to stay on pure sqlpage.

So I send the result in a table and try to use one row of this table as argument in the select component but with the problem as it seems to be difficult to introduce a sub-query in a select query without an external function in python.

I tried to use json_array but I am still stuck.

So someone has an idea, thanks to him or her !

[lovasoa]

Hello!

If I understand well, you want to let users download a csv with a variable number of columns. This is quite unusual, but possible. You can use the dynamic component to pass a json array of objects to the csv component, and json_group_object to generate the objects with a variable number of properties.

Overall, this is much more complicated than just selecting the subset of columns to download yourself. Isn't there a few subset of columns that make sense together and they you could offer your users a hard coded options?

[lovasoa]

another option is to download a csv with all columns all the time, but leave the contents of the columns you don't need empty:

select 'csv' as component; 
select 
  case when $col1 is null then '' else col1 end as col1,
  case when $col2 is null then '' else col2 end as col2
from my_table

[SebastiendOrnano]

I will do the simple way and I will prepare preset subsets (i.e : name/email or name/phone or name/birthday, ...) !

Thanks again