Hello,

I’m having a bit of trouble creating a function with EctoMulti. I have support_tickets which have many support_ticket_messages. When I want to insert new message, I have the following function which takes the attrs and puts association to ticket and user and this function works just fine.

def create_support_ticket_message(%SupportTicket{} = ticket, %User{} = user, attrs) do
    %SupportTicketMessage{seen: false}
    |> SupportTicketMessage.changeset(attrs)
    |> Ecto.Changeset.put_assoc(:support_ticket, ticket)
    |> Ecto.Changeset.put_assoc(:user, user)
    |> Repo.insert()
end

Now, I want to send notification to the user when new message is created so I wanted to use Ecto.Multi() but I’m not sure how to write it properly. The following function doesn’t work because I need to use a function to use Ecto.build_assoc() and I have only a changeset which contain message attrs.

changeset = SupportTicketMessage.changeset(attrs)

Multi.new()
    |> Multi.insert(:support_ticket_message, changeset ->
        Ecto.build_assoc(ticket, :support_ticket_messages)
        Ecto.build_assoc(user, :user)
      end)
    |> Repo.transaction()

How to write this function properly?