许多一对多的关系只能单向的Rails / ActiveRecord的/色器件 [英] Many-to-Many relationship only works one way Rails / Activerecord / devise
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问题描述
我有很多一对多的关系，用户到列表 用色器件创建用户模型。
出于某种原因，我不能对任何用户访问.lists。返回未定义的方法`to_sym'的零：NilClass。
在做一些挖掘IM pretty的肯定香港专业教育学院后发现问题 _reflect_on_associationactiverecord（4.1.6）的lib / active_record / reflection.rb
高清_reflect_on_association（协会）＃：nodoc：
_reflections [association.to_sym]
结束
协会正在传递中作为零。
有没有人碰到这个问题？
在轨控制台测试关系
[15]撬（主）＆GT; testuser的= User.new
=＆GT; ＃＆lt;使用者ID：无，电子邮件：，encrypted_password：，reset_password_token：无，reset_password_sent_at：无，remember_created_at：无，sign_in_count：0，current_sign_in_at：无，last_sign_in_at：无，current_sign_in_ip：无，last_sign_in_ip：无， created_at：无，的updated_at：无，提供者：无，UID：无，名：无，图像：无＆GT;
[16]撬（主）＆GT; testlist = List.new
=＆GT; ＃＆LT;列表ID：无，名：无，created_at：无，的updated_at：无＆GT;
[17]撬（主）＆GT; testlist.users
=＆GT; []
[18]撬（主）＆GT; testuser.lists
NoMethodError：未定义的方法`to_sym'的零：NilClass
从/Users/user/.rvm/gems/ruby-2.1.2/gems/activerecord-4.1.6/lib/active_record/reflection.rb:100:in`_reflect_on_association
[19]撬（主）＆GT; testlist.users＆LT;＆LT; testuser的
=＆GT; [＃＆lt;使用者ID：无，电子邮件：，encrypted_password：，reset_password_token：无，reset_password_sent_at：无，remember_created_at：无，sign_in_count：0，current_sign_in_at：无，last_sign_in_at：无，current_sign_in_ip：无，last_sign_in_ip：无，created_at：无，的updated_at：无，提供者：无，UID：无，名：无，图像：无＆GT;]
[22]撬（主）＆GT; testuser.lists＆LT;＆LT; testlist
NoMethodError：未定义的方法`to_sym'的零：NilClass
从/Users/user/.rvm/gems/ruby-2.1.2/gems/activerecord-4.1.6/lib/active_record/reflection.rb:100:in`_reflect_on_association
模式
列表模型
类List＆LT;的ActiveRecord :: Base的
的has_many：注意事项
的has_many：list_users
的has_many：用户通过：list_users
结束
用户模型（色器件）
类用户的LT;的ActiveRecord :: Base的
＃包括默认色器件模块。可用其他人则：
＃：可确定，：可锁定，：timeoutable和：omniauthable
设计：database_authenticatable，：可注册，
：可恢复的，：rememberable，：可追踪，：可验证
设计：omniauthable，：omniauth_providers =＆GT; [：脸谱，：叽叽喳喳]
的has_many：list_users
的has_many：列表，通过：list_users
高清self.from_omniauth（AUTH）
其中，（提供者：auth.provider，UID：auth.uid）.first_or_create做|用户|
user.email = auth.info.email
user.password的= Devise.friendly_token [0,20]
user.name = auth.info.name＃假设用户模型有一个名字
user.image = auth.info.image＃假设用户模型有一个形象
结束
结束
高清self.new_with_session（参数，可以会话）
super.tap做|用户|
如果数据=会话[devise.facebook_data]＆功放;＆安培;会议[devise.facebook_data] [额外] [raw_info]
user.email =数据[电子邮件]如果user.email.blank？
结束
结束
结束
结束
LISTUSER模型（连接表）
类LISTUSER＆LT;的ActiveRecord :: Base的
belongs_to的：注意事项
belongs_to的：用户
结束
模式
CREATE_TABLElist_users，力：真正做| T |
t.integerlist_id
t.integerUSER_ID
t.datetimecreated_at
t.datetime的updated_at
结束
CREATE_TABLE名单，力：真正做| T |
t.string名
t.datetimecreated_at
t.datetime的updated_at
结束
CREATE_TABLE用户，力：真正做| T |
t.string电子邮件，默认：空：假的
t.stringencrypted_password，默认：空：假的
t.stringreset_password_token
t.datetimereset_password_sent_at
t.datetimeremember_created_at
t.integersign_in_count，默认值：0，零：假的
t.datetimecurrent_sign_in_at
t.datetimelast_sign_in_at
t.inetcurrent_sign_in_ip
t.inetlast_sign_in_ip
t.datetimecreated_at
t.datetime的updated_at
t.string供应商
t.stringUID
t.string名
t.string形象
结束
add_index用户，[电子邮件]，名称：index_users_on_email，独特的：真正的，使用：：B树
add_index用户，[reset_password_token]，名称：index_users_on_reset_password_token，独特的：真正的，使用：：B树
结束
解决方案
比较晚，但是还面临着同样的问题我自己。
这似乎后者导轨没有指定的信息关联的问题了原因;请尝试更改您的LISTUSER型号belongs_to的关联名称。
我想这应该是这样的：
类LISTUSER＆LT;的ActiveRecord :: Base的
belongs_to的：列表
belongs_to的：用户
结束
I have a many-to-many relationship User to Lists User model was created with devise.
For some reason I cant access .lists on any of the users. returns undefined method `to_sym' for nil:NilClass.
after doing some digging im pretty sure ive found the problem in _reflect_on_associationactiverecord (4.1.6) lib/active_record/reflection.rb
def _reflect_on_association(association) #:nodoc:
_reflections[association.to_sym]
end
association is being passed in as nil.
Has anyone run into this problem before?
Testing relationship in rails console
[15] pry(main)> testuser = User.new
=> #<User id: nil, email: "", encrypted_password: "", reset_password_token: nil, reset_password_sent_at: nil, remember_created_at: nil, sign_in_count: 0, current_sign_in_at: nil, last_sign_in_at: nil, current_sign_in_ip: nil, last_sign_in_ip: nil, created_at: nil, updated_at: nil, provider: nil, uid: nil, name: nil, image: nil>
[16] pry(main)> testlist = List.new
=> #<List id: nil, name: nil, created_at: nil, updated_at: nil>
[17] pry(main)> testlist.users
=> []
[18] pry(main)> testuser.lists
NoMethodError: undefined method `to_sym' for nil:NilClass
from /Users/user/.rvm/gems/ruby-2.1.2/gems/activerecord-4.1.6/lib/active_record/reflection.rb:100:in `_reflect_on_association'
[19] pry(main)> testlist.users << testuser
=> [#<User id: nil, email: "", encrypted_password: "", reset_password_token: nil, reset_password_sent_at: nil, remember_created_at: nil, sign_in_count: 0, current_sign_in_at: nil, last_sign_in_at: nil, current_sign_in_ip: nil, last_sign_in_ip: nil, created_at: nil, updated_at: nil, provider: nil, uid: nil, name: nil, image: nil>]
[22] pry(main)> testuser.lists << testlist
NoMethodError: undefined method `to_sym' for nil:NilClass
from /Users/user/.rvm/gems/ruby-2.1.2/gems/activerecord-4.1.6/lib/active_record/reflection.rb:100:in `_reflect_on_association'
Models
List Model
class List < ActiveRecord::Base
has_many :notes
has_many :list_users
has_many :users, through: :list_users
end
User Model (devise)
class User < ActiveRecord::Base
# Include default devise modules. Others available are:
# :confirmable, :lockable, :timeoutable and :omniauthable
devise :database_authenticatable, :registerable,
:recoverable, :rememberable, :trackable, :validatable
devise :omniauthable, :omniauth_providers => [:facebook, :twitter]
has_many :list_users
has_many :lists, through: :list_users
def self.from_omniauth(auth)
where(provider: auth.provider, uid: auth.uid).first_or_create do |user|
user.email = auth.info.email
user.password = Devise.friendly_token[0,20]
user.name = auth.info.name # assuming the user model has a name
user.image = auth.info.image # assuming the user model has an image
end
end
def self.new_with_session(params, session)
super.tap do |user|
if data = session["devise.facebook_data"] && session["devise.facebook_data"]["extra"]["raw_info"]
user.email = data["email"] if user.email.blank?
end
end
end
end
ListUser Model (join table)
class ListUser < ActiveRecord::Base
belongs_to :note
belongs_to :user
end
Schema
create_table "list_users", force: true do |t|
t.integer "list_id"
t.integer "user_id"
t.datetime "created_at"
t.datetime "updated_at"
end
create_table "lists", force: true do |t|
t.string "name"
t.datetime "created_at"
t.datetime "updated_at"
end
create_table "users", force: true do |t|
t.string "email", default: "", null: false
t.string "encrypted_password", default: "", null: false
t.string "reset_password_token"
t.datetime "reset_password_sent_at"
t.datetime "remember_created_at"
t.integer "sign_in_count", default: 0, null: false
t.datetime "current_sign_in_at"
t.datetime "last_sign_in_at"
t.inet "current_sign_in_ip"
t.inet "last_sign_in_ip"
t.datetime "created_at"
t.datetime "updated_at"
t.string "provider"
t.string "uid"
t.string "name"
t.string "image"
end
add_index "users", ["email"], name: "index_users_on_email", unique: true, using: :btree
add_index "users", ["reset_password_token"], name: "index_users_on_reset_password_token", unique: true, using: :btree
end
解决方案
Quite late, but just have faced the same issue myself.
It seems latter rails don't specify causes of association issues in details anymore; try changing belongs_to association name in your ListUser model.
I guess it should be this way:
class ListUser < ActiveRecord::Base
belongs_to :list
belongs_to :user
end
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