Question

我是Elixir和Phoenix的新人。我试图使用mix ecto.migrate为少数迁移文件运行迁移，但它会抛出此错误，

18:27:24.471 [info]  == Running FatLobster.Repo.Migrations.CreateRecipeTable.change/0 forward
** (Ecto.MigrationError) cannot execute command outside of block
    (ecto) lib/ecto/migration/runner.ex:139: Ecto.Migration.Runner.subcommand/1
    _build/dev/lib/fat_lobster/priv/repo/migrations/20160423115340_create_recipe_table.exs:5: FatLobster.Repo.Migrations.CreateRecipeTable.change/0
    (stdlib) timer.erl:197: :timer.tc/3
    (ecto) lib/ecto/migration/runner.ex:25: Ecto.Migration.Runner.run/6
    (ecto) lib/ecto/migrator.ex:121: Ecto.Migrator.attempt/6
    (ecto) lib/ecto/migrator.ex:71: anonymous fn/4 in Ecto.Migrator.do_up/4
    (ecto) lib/ecto/pool.ex:292: Ecto.Pool.with_rollback/3
    (ecto) lib/ecto/adapters/sql.ex:582: Ecto.Adapters.SQL.transaction/8
    (ecto) lib/ecto/pool.ex:244: Ecto.Pool.outer_transaction/6
    (ecto) lib/ecto/adapters/sql.ex:551: Ecto.Adapters.SQL.transaction/3
    (ecto) lib/ecto/migrator.ex:226: anonymous fn/4 in Ecto.Migrator.migrate/4
    (elixir) lib/enum.ex:1088: Enum."-map/2-lists^map/1-0-"/2
    (ecto) lib/mix/tasks/ecto.migrate.ex:63: anonymous fn/4 in Mix.Tasks.Ecto.Migrate.run/2
    (elixir) lib/enum.ex:604: Enum."-each/2-lists^foreach/1-0-"/2
    (elixir) lib/enum.ex:604: Enum.each/2
    (mix) lib/mix/cli.ex:58: Mix.CLI.run_task/2
    (elixir) lib/code.ex:363: Code.require_file/2

这是迁移，

defmodule FatLobster.Repo.Migrations.CreateRecipeTable do
  use Ecto.Migration

  def change do
    add :recipe_title, :string
    add :recipe_description,  :string

    add :cover_img, :string
    add :picture_one, :string
    add :picture_two, :string
    add :picture_three, :string

    add :user_id, :integer
    add :upvote_count, :integer
    add :downvote_count, :integer

    timestamps
  end
end

现在，这里到底出了什么问题？我真的失踪了什么？我应该寻找具体的东西吗？

Answer 1

您错过了create table(...)区块：

defmodule FatLobster.Repo.Migrations.CreateRecipeTable do
    use Ecto.Migration

    def change do
        create table(:recipes) do
            add :recipe_title, :string
            add :recipe_description,  :text
            add :cover_img, :string
            add :picture_one, :string
            add :picture_two, :string
            add :picture_three, :string

            add :user_id, :integer
            add :upvote_count, :integer
            add :downvote_count, :integer

            timestamps
        end
    end
end

此处有更多信息：https://hexdocs.pm/ecto/Ecto.Migration.html#create/1

运行ecto迁移时出错

1 个答案: