ActiveModel :: UnknownAttributeError:播种belongs_to关系时为未知属性 [英] ActiveModel::UnknownAttributeError: unknown attribute when seeding belongs_to relationship

问题描述

尝试建立has_many/belongs_to关系. 一个用户有多个脚本，一个脚本属于一个用户.

Trying to seed a has_many/belongs_to relationship. A user has_many scripts, a script belongs_to a user.

在播种脚本时，出现此错误:

When seeding the script, I get this error:

ActiveModel :: UnknownAttributeError:的未知属性'user_id' 脚本.

ActiveModel::UnknownAttributeError: unknown attribute 'user_id' for Script.

我认为迁移中的这一行会为脚本创建一个user_id属性吗?

I'd think that this line in my migration would create a user_id attribute for script?

t.belongs_to :user, index: true, foreign_key: true

app/models/script.rb

class Script < ApplicationRecord
  belongs_to :user
  has_many :commits
  has_many :script_users, through: :commits, source: :user
end

app/models/user.rb

class User < ActiveRecord::Base
  has_many :scripts
  has_many :used_scripts, through: :commits, source: :script
  has_many :commits
end

db/migrate/20171231022826_create_scripts.rb

class CreateScripts < ActiveRecord::Migration[5.1]
  def change
    create_table :scripts do |t|
      t.string :name
      t.string :skill
      t.string :bot_for
      t.string :game_for

      t.belongs_to :user, index: true, foreign_key: true

      t.timestamps
    end
  end
end

db/seeds.rb

admin = User.create!(
  email: '[e-mail]',
  password: 'adminadmin',
  password_confirmation: 'adminadmin'
)

script = Script.create!(
  name: 'YWoodcutter',
  skill: 'Woodcutting',
  bot_for: 'Android',
  game_for: "CandyLand,
  user_id: admin.id
)

ActiveModel :: UnknownAttributeError:的未知属性'user_id' 脚本. 我已经确保rake:db reset并仍然出现错误.

ActiveModel::UnknownAttributeError: unknown attribute 'user_id' for Script. I've made sure to rake:db reset and still get error.

谢谢

更新:

我做了几件事，现在一切正常.我认为问题可能在于我的用户迁移是在脚本迁移之后创建的.用户迁移应该在脚本之前完成，因此我更改了日期以更改迁移顺序. db:reset也很有效.

I did a few things and it's working OK now. I believe the issue may have been that my user migration was created after my script migration. The user migration should done before scripts, so I changed the dates to change the order they were migrated in. Did a rake rake db:rollback & db:reset for good measure too.

推荐答案

belongs_to是reference的别名，应与references

如果它不适合您，请尝试以下解决方案

If its not working for you just try with following solution

class CreateScripts < ActiveRecord::Migration[5.1]
  def change
    create_table :scripts do |t|
      t.string :name
      t.string :skill
      t.string :bot_for
      t.string :game_for

      t.references :user, index: true, foreign_key: true

      t.timestamps
    end
  end
end

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