Many to many with added field

Questions / Help
2

Finally i got this works. I added schema to join table and use has_many through: function. These are the latest schemas.

defmodule App.Sale do
  use App.Web, :model
  alias App.SaleItem

  schema "sales" do
    field :number, :integer
    has_many :sales_items, SaleItem, on_delete: :delete_all
    has_many :items, through: [:sales_items, :item]
  end
end

defmodule App.Item do
  use App.Web, :model
  alias App.SaleItem
  
  schema "items" do
    field :name, :string
    has_many :sales_items, SaleItem, on_delete: :delete_all
    has_many :sales, through: [:sales_items, :sale]
  end
end

defmodule App.SaleItem do
  use App.Web, :model
  alias App.Sale
  alias App.Item
  
  schema "sales_items" do
    belongs_to :sale, Sale
    belongs_to :item, Item
    field :quantity, :integer
  end
end

To get the data i used (simplified)

# preload the association
sale = Repo.get!(Sale, id) |> Repo.preload([:items])

sale.sales_items.quantity
sale.sales_items.item.name
# don't forget to loops the sales_items!

Hope this helps.

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