“警告:不能批量分配受保护的属性" [英] "WARNING: Can't mass-assign protected attributes"
问题描述
我使用了 RESTful 技术来生成模型(实际上，我使用的是 Devise gem，它为我完成了这项工作)，并且我向模型添加了名为 first_name 和 last_name 的新字段.迁移很顺利.我在模型中添加了 attr_accessor :first_name, :last_name 并希望它可以正常工作.但是当我尝试使用 Doctor.create({:first_name=>"MyName"}) 等批量分配新实例时，我收到错误消息，说我无法批量分配受保护的属性.
I have used RESTful techniques to generate a model (in fact, I am using Devise gem, which does that for me), and I have added new fields called first_name and last_name to the model. Migration went fine. I added attr_accessor :first_name, :last_name to the model and expected it would just work. But when I try to mass-assign new instances with Doctor.create({:first_name=>"MyName"}) etc., I am getting errors saying I can't mass-assign protected attributes.
我认为使用 attr_accessor 的全部目的是绕过模型字段的保护.你能帮我理解这条消息吗?
I thought the whole point of using attr_accessor was to get around the protectedness of the fields of a model. Can you help me make sense of this message?
哦，顺便说一下，记录也没有被创建.我认为它们应该是，因为这只是一个警告，但它们不在数据库中.
oh, and by the way the records do not get created either. I thought they should be since this is just a warning, but they are not on the database.
Edit2:这是我的模型
here is my model
class Doctor < User
has_many :patients
has_many :prescriptions, :through=> :patients
validates_presence_of :invitations, :on => :create, :message => "can't be blank"
attr_accessor :invitations
end
和模式，它没有 first_name 和 last_name，因为它们是在 users 表中创建的，这是医生的祖先.我使用了单表继承.
and the schema, which doesn't have the first_name and last_name because they are created in the users table, which is the ancestor of doctors. I used single table inheritance.
create_table :doctors do |t|
t.integer :invitations
t.timestamps
end
这是改变用户表的迁移
add_column :users, :first_name, :string
add_column :users, :last_name, :string
add_column :users, :type, :string
这是种子文件.我不包括 truncate_db_table 方法，但它有效.
here is the seed file. I am not including the truncate_db_table method, but it works.
%w{doctors patients}.each do |m|
truncate_db_table(m)
end
Doctor.create(:invitations=>5, :email=>"email@gmail.com", :first_name=>"Name", :last_name=>"LastName")
Patient.create(:doctor_id=>1, :gender=>"male", :date_of_birth=>"1991-02-24")
推荐答案
不要将 attr_accessor 与 attr_accessible 混淆.访问器内置于 Ruby 中并定义了一个 getter 方法 - model_instance.foo #return something - 和一个 setter 方法 - model_instance.foo = 'bar'.
Don't confuse attr_accessor with attr_accessible. Accessor is built into Ruby and defines a getter method - model_instance.foo # returns something - and a setter method - model_instance.foo = 'bar'.
Accessible 是由 Rails 定义的，并且使属性可以批量赋值(与 attr_protected 相反).
Accessible is defined by Rails and makes the attribute mass-assignable (does the opposite of attr_protected).
如果 first_name 是模型数据库表中的一个字段，则 Rails 已经为该属性定义了 getter 和 setter.您需要做的就是添加 attr_accessible :first_name.
If first_name is a field in your model's database table, then Rails has already defined getters and setters for that attribute. All you need to do is add attr_accessible :first_name.
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