elixir - key :user_id not found in. Elixir 预加载问题

Question

我在构建联盟结构时尝试添加 user_id，但出现此错误:

** (KeyError) key :user_id not found in: %{__meta__: #Ecto.Schema.Metadata<:built, "leagues">, __struct__: Statcasters.Schema.League, id: nil, inserted_at: nil, name: nil, teams: #Ecto.Association.NotLoaded<association :teams is not loaded>, updated_at: nil, users: #Ecto.Association.NotLoaded<association :users is not loaded>, users_id: nil}
(stdlib) :maps.update(:user_id, {{:., [line: 14], [{:user, [line: 14], nil}, :id]}, [line: 14], []}, %{__meta__: #Ecto.Schema.Metadata<:built, "leagues">, __struct__: Statcasters.Schema.League, id: nil, inserted_at: nil, name: nil, teams: #Ecto.Association.NotLoaded<association :teams is not loaded>, updated_at: nil, users: #Ecto.Association.NotLoaded<association :users is not loaded>, users_id: nil})

这是我的 Controller :

联盟管理员

  def new(conn, _params) do
    user = Repo.get!(User, conn.assigns.current_user.id)
    changeset = %League{user_id: user.id}
      |> League.changeset()

    render(conn, "new.html", changeset: changeset)
  end

模型

联赛.ex

  schema "leagues" do
    field :name, :string
    has_many :teams, Statcasters.Teams.Team
    belongs_to :users, Statcasters.Coherence.User

    timestamps()
  end

用户.ex

  schema "users" do
    field :name, :string
    field :email, :string
    coherence_schema()
    has_many :leagues, Statcasters.Schema.League

    timestamps()
  end

我需要使用 Repo.preload 吗？我不确定它要我做什么？

Answer 1

如果您仔细查看错误，它会显示 :user_id not found。实际上它不存在于打印的 map 中，但 :users_id 确实存在。这只能意味着您有一个名为 users 而不是 user 的关系，这正是问题所在。 belongs_to :users 应该是 belongs_to :user。