Ecto bulk delete in a many to many relation

I’m writing this from the top of the head, but you should be able to do this:

attrs = Enum.map(list, fn %{sku_id: sku_id, store_id: store_id} -> {sku_id, store_id} end)

Repo.delete_all(
  from s in SkuStore,
  where: {s.sku_id, s.store_id} in ^attrs
)

Thanks a lot, @stefanchrobot
That’s a great approach and it’s more or less what I’ve been trying to do with no success.
In this case, I would have something like this [{1, 2}, { 3, 4}] to compare with .

But it gives me now an error that I’m still trying to debug and have no idea why it’s happening. It makes no sense to me:

(Ecto.Query.CompileError) Tuples can only be used in comparisons with literal tuples of the same size

Why it’s telling me tuples are not the same size? Makes no sense

Using this answer Ecto IN clauses with tuples - #16 by alex_weinberger I could do it. So at the end, this is what I did:

def delete_skus_by_id(list) do
    queryable =
      from s in SKUStore,
        inner_join:
          j in fragment(
            "SELECT DISTINCT * FROM jsonb_to_recordset(?) AS j(sku_id int, store_id int)",
            ^list
          ),
        on: s.sku_id == j.sku_id and s.store_id == j.store_id

    Ecto.Multi.new()
    |> Ecto.Multi.delete_all(:delete_all, queryable, on_conflict: :nothing)
    |> Repo.transaction()
    |> case do
      {:ok, _} ->
        %{rows_affected: length(list), errors: []}

      {
        :error,
        _,
        %Ecto.Changeset{
          changes: changes,
          errors: errors
        },
        _
      } ->
        %{
          rows_affected: 0,
          errors: "Changes #{changes} couldn't be created because #{inspect(errors)}"
        }
    end
  end

I think I’ve hit this before too. I think this means you need to use explicit values (not even variable) to make this work.