函数App.Support.Ticket.changeset / 2是未定义的或私有的

Question

我刚刚完成了Elixir课程，现在我正在修改运行一个基于Phoenix 1.3的项目，项目编译得很好，本地服务器启动没有任何错误，但是当我尝试打开我收到错误的链接：

以下是account.ex文件的代码：

defmodule App.Account do

  alias App.Repo
  alias Xarango.Query

  alias App.Account.User

  def list_users do
    User.list(%{})
  end

  def get_user!(id) do
    try do
      {:ok, User.one(%{_key: id})}
      rescue
      e in Xarango.Error ->
        {:error, :not_found}
    end
  end

  def get_user_by_attr(attr) do
    try do
      {:ok, User.one(attr)}
    rescue
      Xarango.Error ->
        key = attr
          |> Map.keys
          |> List.first
          |> Atom.to_string
        {:error, "#{key} not found"}
    end
  end

  def check_credentials(%{"password" => password, "email" => email}) do
    with {:ok, user} <- get_user_by_attr(%{email: email}) do
      if password = user.doc._data.password do
        {:ok, user}
      else
        {:error, "Incorrect password"}
      end
    end
  end

  def create_user(%{"email" => email, "nick" => nick} = attrs, roles) when is_list(roles) do
    with {:ok, _resp} <- check_if_attr_exists(%{email: email}),
         {:ok, _resp} <- check_if_attr_exists(%{nick: nick}),
         {:ok, user} <- get_avatar(attrs) do
      {:ok, user |> Map.put("roles", roles) |> User.create}
    end
  end

  defp get_avatar(%{"email" => email} = attrs) do
    hash_email = :crypto.hash(:md5, email) |> Base.encode16
    {:ok, Map.put(attrs, "avatar", "https://api.adorable.io/avatars/100/#{hash_email}")}
  end

  defp check_if_attr_exists(attr) do
    try do
      User.one(attr)
      key = attr
            |> Map.keys
            |> List.first
            |> Atom.to_string
      {:error, "#{key} already exists"}
    rescue
      Xarango.Error ->
        {:ok, :continue}
    end
  end

  def hash_password(%{"password" => password} = attrs) do
    with {:ok} <- valid_password?(password),
         %{password: _, password_hash: password} <- password do
      {:ok, Map.put(attrs, "password", password)}
    end
  end

  defp valid_password?(password) when byte_size(password) > 6 do
    {:ok}
  end

  defp valid_password?(_), do: {:error, "The password is to short"}

  def update_user(%User{} = user, attrs) do
    user
    |> User.changeset(attrs)
    |> Repo.update()
  end

  def delete_user(%User{} = user) do
    Repo.delete(user)
  end

  def change_user(%User{} = user) do
    User.changeset(user, %{})
  end

  alias App.Account.Client

    Query.query(q).result
  end

  def get_client!(id) do
    q = """
    FOR c IN clients
        FILTER c._key == #{id}
        RETURN c
    """
    List.first Query.query(q).result
  end

  def create_client(attrs \\ %{}) do
    %Client{}
    |> Client.changeset(attrs)
    |> Repo.insert()
  end


  def update_client(%Client{} = client, attrs) do
    client
    |> Client.changeset(attrs)
    |> Repo.update()
  end


  def delete_client(%Client{} = client) do
    Repo.delete(client)
  end


  def change_client(%Client{} = client) do
    Client.changeset(client, %{})
  end
end

这是我的client.ex文件：

defmodule App.Account.Client do
  use Xarango.Domain.Document, collection: :clients

end

以下是我的ticket_controller.ex文件的一部分：

defmodule AppWeb.TicketController do
  use AppWeb, :controller

  alias App.Support
  alias App.Support.Ticket

  action_fallback AppWeb.FallbackController

  def index(conn, _params) do
    IO.inspect(Support.create_ticket())
    tickets = Support.list_tickets()
    render(conn, "index.json", tickets: tickets)
  end

更新我在这里也提供了我的ticket.ex文件的代码（App.Support.Ticket）：

defmodule App.Support.Ticket do
  use Xarango.Domain.Document, collection: :helpdesk_tickets


end

有什么想法吗？有人可以解释一下我到底做错了什么吗？

更新2：我在文件夹/lib/app/repo.ex中添加了一个文件repo.ex，这是我从工作项目中获取的：

defmodule App.Repo do
  use Ecto.Repo, otp_app: :app

  @doc """
  Dynamically loads the repository url from the
  DATABASE_URL environment variable.
  """
  def init(_, opts) do
    {:ok, Keyword.put(opts, :url, System.get_env("DATABASE_URL"))}
  end
end

我还修复了ecto的一个问题：

(CompileError) lib/app/repo.ex:2: module Ecto.Repo is not loaded and could not be found
   (elixir) expanding macro: Kernel.use/2
   lib/app/repo.ex:2: App.Repo (module)
   (elixir) lib/kernel/parallel_compiler.ex:198: anonymous fn/4 in Kernel.ParallelCompiler.spawn_workers/6

我通过添加{：phoenix_ecto，＆＃34;〜＆gt;来修复它3.2＆＃34;}使用mix.exs和runnig＆＃34;＆gt;混合deps.get＆＃34;。 现在我有一个新错误：

== Compilation error in file lib/app/repo.ex ==
** (ArgumentError) missing :adapter configuration in config :app, App.Repo
    lib/ecto/repo/supervisor.ex:70: Ecto.Repo.Supervisor.compile_config/2
    lib/app/repo.ex:2: (module)
    (stdlib) erl_eval.erl:670: :erl_eval.do_apply/6
    (elixir) lib/kernel/parallel_compiler.ex:198: anonymous fn/4 in Kernel.ParallelCompiler.spawn_workers/6

有人可以建议我现在应该解决什么问题吗？我觉得这个错误出现了，因为我从连接到PostgresDB的项目复制了repo.ex文件，而我当前的项目连接到ArangoDB。