多对多通过关联在 Rails 应用程序中构建/创建属性 [英] Many-to-Many through association Build/Create properties in Rails app

问题描述

以下类相互关联(第一个没有教程的 rails 应用程序):

The following classes associate with each other (first rails app without a tutorial):

class Team < ActiveRecord::Base
  has_many :team_users, :class_name => "TeamUser"
  has_many :users, :through => :team_users
end

class TeamUser < ActiveRecord::Base
  belongs_to :user
  belongs_to :team
end

class User < ActiveRecord::Base
  has_many :team_users, :class_name => "TeamUser"
  has_many :teams, :through => :team_users
end

如果我有用户属性，在尝试执行以下操作时:

If I have user attribute, when trying to do the following:

u.teams.build(:name => "catsteam", :captain => true, :owner => :true)

Captain 和 Owner 是 TeamUser 类的属性.执行命令我得到以下内容:

Captain and Owner are properties of the TeamUser class. Executing the command I get the following:

u.teams.build(:name => "catsteam", :captain => true, :owner => :true)
ActiveRecord::UnknownAttributeError: unknown attribute: captain
...
from -e:1:in `load'
from -e:1:in `<main>'

附带说明，如果我获得用户，创建团队，然后创建团队用户，一切正常.我很困惑，已经搜索过但找不到任何东西.

On a side note if I get the user, create the team, then create the teamuser all works. I am so confused and have searched but cannot find anything.

谢谢.

推荐答案

u.teams 指的是 Team 实例.使用此命令，您正在构建 Team 实例，因此船长和所有者不被识别也就不足为奇了，因为它们是 TeamUser 的属性而不是用户.您应该分 2 个步骤执行此操作:

u.teamsrefers to Team instances. With this command you are building Team instances so it is no surprise that captain and owner are not recognized as they are attributes of TeamUser and not user. You should do this in 2 steps:

team = Team.create
team_user = u.team_users.build(:team_id => team.id)

当然，如果您在 team_user 上遇到验证错误，您可能希望根据您的应用程序销毁您的团队.

Of course if you encounter a validation error on your team_useryou might want to destroy your team depending on your application.

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