Ecto join and order_by with dynamic values

This is probably what you’re looking for.

@LostKobrakai Yesss, This definitely helped! Now the only thing left is to make the “asc” and “desc” dynamic. Since I cannot use [ “#{filters[“order”]}”: field(e, ^order_field) ] in the query. Got any ideas on that?

You can create the order_by list outside of the query and interpolate the whole list:

values = [asc: :name, desc: :population]
from(c in City, order_by: ^values)

That should allow it to be dynamically generated.

@mbuhot Have tried that already, but there is no way I can acces the joined table field. Like this will not work:

values = [asc: field(c, :name)]
from(
    e in query,
    join: c in assoc(e, :city)
    order_by: ^values
  )

Doesn’t …, order_by: [{^direction, field(e, ^field)}] work?

@LostKobrakai Yes! This is it! Strange that this way of writing it is not in the docs for order_by. Would be great to note that, unless it’s written somewhere else I don’t know of.. But in any case, thanks!

Here is the final result and solution (according to my case):

order_field = String.to_atom(filters["order_by"])
direction = String.to_atom(filters["order"])
  from(
      ue in query,
      join: e in assoc(ue, :event),
      order_by: [{^direction, field(e, ^order_field)}]
    )