没有将数组隐式转换为字符串 - Rails 迁移

Question

尝试在新计算机上启动并运行应用程序。可能使用的是略微更新的Ruby版本（2.3.4与2.3.1），Rails版本是5.1.3。

以下是迁移：

class AddDragAndDropRules < ActiveRecord::Migration[5.0]
  def change
    add_column :products, :fixture_location, :string, default: "none"
    add_column :products, :attaches_to, :uuid, array: true, default: []
  end
end

rails db:migrate期间的问题。

错误：

== 20160928162420 AddDragAndDropRules: migrating ==============================
-- add_column(:products, :fixture_location, :string, {:default=>"none"})
   -> 0.0142s
-- add_column(:products, :attaches_to, :uuid, {:array=>true, :default=>[]})
rails aborted!
StandardError: An error has occurred, this and all later migrations canceled:
no implicit conversion of Array into String
/Users/mike/api/db/migrate/20160928162420_add_drag_and_drop_rules.rb:4:in `change'
bin/rails:9:in `require'
bin/rails:9:in `<main>'
TypeError: no implicit conversion of Array into String
/Users/mike/api/db/migrate/20160928162420_add_drag_and_drop_rules.rb:4:in `change'
bin/rails:9:in `require'
bin/rails:9:in `<main>'
Tasks: TOP => db:migrate
(See full trace by running task with --trace)

有人能够发现错误吗？

Answer 1

如果这对其他人有帮助 - 该项目在某个时候升级到 Rails 5.1.3，这导致 UUID 数组迁移由于错误而失败。

问题在这里（https://github.com/rails/rails/issues/30539），5.1.2-5.1.3 中的解决方法是执行以下操作：

add_column :products, :attaches_to, :uuid, array: true, default: '{}'

应在 5.1.4 及更高版本中修复。