Problem with a query when upgrading from Ecto 3.5.0

Questions / Help
#1

I have this query that worked in Ecto 3.4.6 but does not work in Ecto 3.5.0 or later
EDIT: I wrongly assumed that setting ecto_sql at 3.5.0 also sets ecto at 3.5.0 but it was higher.

from cm in q,
  where:
    not exists(
      fragment(
        """
        SELECT *
        FROM member_tag_assignments
        WHERE tag_id = ANY(?) AND club_member_id = ?
        """,
        type(^secondary_lookup.tag_ids, {:array, :binary_id}),
        cm.id
      )
    )

After upgrade it says:

== Compilation error in file lib/clubbase/club_member_search/club_member_search.ex ==
** (CompileError) lib/clubbase/club_member_search/club_member_search.ex:339: cannot use ^secondary_lookup.tag_ids outside of match clauses

I understand that Elixir thinks it is outside of query but I don’t know why. I have import Ecto.Query at the top. Other queries work OK - only that particular combination of exists and fragment is problematic.

The exists is custom

  defmacro exists(arg) do
    quote do: fragment("EXISTS(?)", unquote(arg))
  end

because it was not yet available back in 3.5

I also tried assigning extracting tag_ids to a variable so that I am not using . inside type but it doesn’t make a difference.

I can’t pinpoint what happened in 3.5 that breaks the query.

#2

The error message seems to indicate that Elixir is not expanding the from correctly. So Elixir then proceeds to expand the arguments and find an invalid ^.

2 Likes
#3

As a start, try and format the from call with parentheses and see if that fixes it?

If not, rename your macro to something not builtin inside Ecto, e.g. our_exists (temporarily!) and use it as before – does that fix it?

To me it looks like it should be working. :thinking:

#4

That is great solution! Awesome advice.