Question

我希望模型Game有两个用户：user1和user2

这是我的两个模型及其迁移：

game.rb：

class Game < ApplicationRecord

has_secure_token

# @!group RELATIONS
has_many :turns, dependent: :destroy
has_many :play_cards, dependent: :destroy
has_one :user1, class_name: 'User', dependent: :destroy
has_one :user2, class_name: 'User', dependent: :destroy
# @!endgroup

# @!group VALIDATORS
validates :user1_id, presence: true, blank: false, nill: false
validates :user2_id, presence: true, blank: false, nill: false
validates :finish_at, presence: true, blank: false, nill: false
validates :token, presence: true, blank: false, nill: false, length: { is: 24 }
# @!endgroup

end

迁移：

def change
create_table :games do |t|
  t.references :user1, foreign_key: { to_table: :users }
  t.references :user2, foreign_key: { to_table: :users }
  t.string :token, length: { is: 24 }, null: false
  t.datetime :finish_at, null: false

  t.timestamps
end
end

user.rb：

class User < ApplicationRecord

has_secure_token :token

# @!group RELATIONS
has_many :decks, dependent: :destroy
has_one :chosen_deck, class_name: 'Deck', dependent: :destroy
has_many :turns, dependent: :destroy
# @!endgroup

# @!group VALIDATORS
validates :hp, presence: true, blank: false, nill: false, numericality: { greater_than_or_equal_to: 0 }
validates :armor, presence: true, blank: false, nill: false, numericality: { greater_than_or_equal_to: 0 }
validates :token, presence: true, blank: false, nill: false, length: { is: 24 }, on: :save
validates :name, presence: true, blank: false, nill: false, length: { minimum: 4 }
# @!endgroup

end

迁移：

create_table :users do |t|
  t.references :chosen_deck, index: true, foreign_key: { to_table: :decks }
  t.string :name, null: false
  t.integer :hp, null: false, default: 20
  t.integer :armor, null: false, default: 0
  t.string :token, length: { is: 24 }, null: false

  t.timestamps
end

当我尝试使用该游戏保存游戏时，会出现问题：

ActiveModel::MissingAttributeError: can't write unknown attribute `game_id`

我在此处放置了一个屏幕截图：error screen

度过愉快的一天，

Answer 1

ActiveModel :: MissingAttributeError：无法写入未知属性game_id

问题在于错误所在。 User模型缺少game_id属性，这是约定用于连接用户和游戏所必需的（如果您想要另一列，则应明确指定为foreign_key）

只需为game_id创建users列，并在belongs_to :game模型中指定（不必要）User，因为用户belongs_to是游戏。

否则，由于您有user1_id和user2_id，因此您需要将has_one更改为belongs_to。然后，它会更新这些belongs_to列，而不是在game_id关联中查找has_one。

class Game < ApplicationRecord
  # @!group RELATIONS
  has_many :turns, dependent: :destroy
  has_many :play_cards, dependent: :destroy
  belongs_to :user1, class_name: 'User', dependent: :destroy
  belongs_to :user2, class_name: 'User', dependent: :destroy
  # @!endgroup
end

Rails与我的关系陷入困境

1 个答案: