友誼自助參考

Question

我一直在試圖實現一個Facebook風格的朋友系統。我讀過幾篇教程，並且無法理解我在做什麼錯誤。友誼控制器和添加好友的視圖中的鏈接工作，但在數據庫級別，它會引發錯誤。

當我打開軌道控制檯，並提出：

User.find(1).friends << User.find(2) 

我得到：

SQL (0.4ms) INSERT INTO "friendships" ("user_id", "friend_id", "created_at", "updated_at") VALUES (?, ?, ?, ?) [["user_id", 1], ["friend_id", 2], ["created_at", "2017-10-14 15:01:28.364691"], ["updated_at", "2017-10-14 15:01:28.364691"]] 
(0.1ms) rollback transaction 
ActiveRecord::StatementInvalid: SQLite3::SQLException: no such table: main.friends: INSERT INTO "friendships" ("user_id", "friend_id", "created_at", "updated_at") VALUES (?, ?, ?, ?) 
from (irb):1 

user.rb

has_many :friendships, dependent: :destroy 
has_many :friends, through: :friendships 

# these are used in the controller 

def befriend(user) 
    friends << user 
end 

def unfriend(user) 
    friends.delete(user) 
end 

def friends?(user) 
    friends.include?(user) 
end 

friendship.rb

belongs_to :user 
belongs_to :friend, class_name: 'User', foreign_key: "friend_id" 

validates :user_id, presence: true 
validates :friend_id, presence: true 

我正在使用Devise進行身份驗證。

Answer 1

您並未創建好友（其他用戶已存在），但友誼。

user.rb

class User < ActiveRecord::Base 
    has_many :friendships, dependent: :destroy 
    has_many :friends, through: :friendships, source: :friend 
end 

friendship.rb

class Friendship < ActiveRecord::Base 
    belongs_to :user 
    belongs_to :friend, class_name: 'User' 
end 

控制檯

User.find(1).friendship.create(friend_id: User.find(2).id)