Question

我试图将uuid与ecto一起使用。我可以查询所有内容，但是我在Repo.get中遇到unable to encode value错误。

defmodule Rocket.Model do
  defmacro __using__(_) do
    quote do
      use Ecto.Model
      @primary_key {:id, :uuid, []}
      @foreign_key_type :uuid
    end
  end
end

defmodule Rocket.User do
  use Rocket.Model

  schema "users" do
    field :created_at, :datetime
    field :name, :string
    field :email, :string
    field :password, :string
    field :timezone, :string
  end
end


iex(37)> Rocket.Repo.get(Rocket.User,"00000000-0000-0000-0000-00000000011b") 
21:51:58.291 [debug] SELECT u0."id", u0."created_at", u0."name", u0."email", u0."password", u0."timezone" FROM "users" AS u0 WHERE (u0."id" = $1) (0.4ms)
** (Postgrex.Error) unable to encode value `"00000000-0000-0000-0000-00000000011b"` as type uuid
      (ecto) lib/ecto/adapters/sql/worker.ex:18: Ecto.Adapters.SQL.Worker.query!/4
      (ecto) lib/ecto/adapters/sql.ex:186: Ecto.Adapters.SQL.use_worker/3
    (rocket) web/models/repo.ex:2: Rocket.Repo.log/2
      (ecto) lib/ecto/adapters/sql.ex:315: Ecto.Adapters.SQL.all/5
      (ecto) lib/ecto/repo/queryable.ex:20: Ecto.Repo.Queryable.all/4
      (ecto) lib/ecto/repo/queryable.ex:43: Ecto.Repo.Queryable.one/4
iex(37)>

使用所有作品，但uuid在控制台或json解码中都没有表示为字符串：

iex(38)> user = Rocket.Repo.all(Rocket.User) |> List.first
21:58:55.450 [debug] SELECT u0."id", u0."created_at", u0."name", u0."email", u0."password", u0."timezone" FROM "users" AS u0 (1.5ms)
%Rocket.User{created_at: %Ecto.DateTime{day: 3, hour: 2, min: 16, month: 1,
  sec: 3, year: 2015}, email: "joel@foo.com",
 id: <<0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 29>>, name: "Joel",
 password: "$1$E0eFWgDt$YgQTEByVT7prYkT2IqBjL1", timezone: nil}
iex(39)> IO.puts Poison.Encoder.encode(udb,[])  
{"timezone":null,"password":"$1$E0eFWgDt$YgQTEByVT7prYkT2IqBjL1","name":"Joel","id":"\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0000\u0001\u001D","email":"joel@foo.com","created_at":{"year":2015,"sec":3,"month":1,"min":16,"hour":2,"day":3}}
:ok

Answer 1

UUID只有16个字节，因此从all/1获得的内容实际上是正确的。如果要使用UUID的详细表示，可以显式转换它或使用自定义类型在将数据加载和转储到数据库时自动为您执行工作。我已经谈到了自定义类型in this answer。

如何在Ecto模型中使用uuid

1 个答案: