Custom aggregations examples

[UserBird]

Hello,

Could you provide some examples of custom aggregations involving an array or a map?

Thank you

[cperdigou]

Here is an example using Postgres

For a complete reference see https://www.postgresql.org/docs/9.5/static/functions-aggregate.html or the reference of the database you use.

[Francis]

Hey thanks for the answer, that helped me. However, I can't seem to use any of PG aggregate functions except group_concat:

https://pasteboard.co/GAjh6rZ.png

Is it normal ?

[cperdigou]

You are probably using MySQL, in that case the answer is yes.
See this SO question:
https://stackoverflow.com/questions/39030090/mysql-array-aggregate-function-like-postgresql-array-agg

[Francis]

I'm actually using PostgreSQL 9.6.3 😕

[Francis]

Do you have any idea why I can't access PostgreSQL aggregate functions from that dashboard? Thx

[Francis]

Ok my bad, the output database was PG but the input was filebased... Works like a charm thanks