Repo.transaction not working in Ecto Multi

script · January 15, 2019, 8:58am

I have this schema:

schema "rooms_units" do
  field(:date_from, :utc_datetime)
  field(:date_to, :utc_datetime)
  belongs_to(:room, App.Room, primary_key: true)
  belongs_to(:unit, App..Unit)
end

In my function I am making list of changesets and pass the list to Multi.insert_all as the room_unit_changeset

Multi.new
|> Multi.insert_all(:room_units, Appr.RoomUnit ,room_unit_changeset)
|> Repo.transaction()

Multi.insert_all returns the output like this:

%Ecto.Multi{
  names: #MapSet<[:room_units]>,
  operations: [
    rooms: {:insert_all, App.RoomUnit,
     [
      #Ecto.Changeset<
        action: nil,
        changes: %{
          date_from: #DateTime<2016-11-03 13:23:00Z>,
          date_to: #DateTime<2016-11-03 13:23:00Z>,
          room_id: 9,
          unit_id: 14
        },
        errors: [],
        data: #App.RoomUnit<>,
        valid?: true
      >,
      #Ecto.Changeset<
        action: nil,
        changes: %{
          date_from: #DateTime<2016-11-03 13:23:00Z>,
          date_to: #DateTime<2016-11-03 13:23:00Z>,
          room_id: 10,
          unit_id: 14
        },
        errors: [],
        data: #App.RoomUnit<>,
        valid?: true
      >,
     ], []}
  ]
}

But Repo.transaction is not working. Returning the server error .
Any help will be much appreciated
thanks

NobbZ · January 15, 2019, 8:59am

Which exactly?

dimitarvp · January 15, 2019, 8:59am

This is too generic. Can you show us the code that constructs the Ecto.Multi object?

script · January 15, 2019, 9:24am

The problem isn’t with the multi object. The ecto multi works fine if i pass single record like this:

Multi.new
  |> Multi.insert(:room_units,  hd(room_unit_changeset))
  |> Repo.transaction()

But insert_all not seems to be working. If you look at the ecto.multi_all result . In the map the action is set to nil. Which i think should be insert like this

%Ecto.Multi{
names: #MapSet<[:room_units]>,
 operations: [
   rooms: {:insert_all, App.RoomUnit,
    [
     #Ecto.Changeset<
    action: :insert,
    changes: %{
      date_from: #DateTime<2016-11-03 13:23:00Z>,
      date_to: #DateTime<2016-11-03 13:23:00Z>,
      room_id: 9,
      unit_id: 14
    },
    errors: [],
    data: #App.RoomUnit<>,
    valid?: true
  >,

script · January 15, 2019, 10:04am

My bad . I thought Ecto.insert_all receives the changesets .But it actually receives the maps. like Repo.insert_all().
On side note is there any function of ecto that supports this multiple chagesets list of maps?
Because i want to validate the params and then insert into the database .

al2o3cr · January 15, 2019, 1:27pm

Two possible approaches for dealing with your list of changesets:

transform it into a series of Multi.insert calls that are then all executed at the end. Note that this will execute one SQL query per changeset, different from the behavior of insert_all.
transform the changesets into structs using Ecto.Changeset.apply_changes and then pass the structs to insert_all.

In both cases, you’ll want to handle changesets with valid?: false carefully; apply_changes, for instance, doesn’t check validity.