Question

在我的Rails项目中，我有一个通过关系命名的has_many Scheme

models / school / contact.rb

[System.Serializable]
public class Edge
{
public Node A;
public Node B;

public Edge (Node A, Node B)
{
    this.A = A;
    this.B = B;
}
}

models / school / contact / email.rb

class School::Contact < ApplicationRecord

  belongs_to :school, class_name: '::School'

  has_many :school_contact_emails, class_name: 'School::Contact::Email'
  has_many :emails, through: :school_contact_emails, class_name: '::Email'

end

models / email.rb

class School::Contact::Email < ApplicationRecord
  belongs_to :school_contact, class_name: 'School::Contact'
  belongs_to :email, class_name: '::Email'
end

如果我打开Rails控制台

class Email < ApplicationRecord
  has_many :school_contact_emails, class_name: 'School::Contact::Email'
  has_many :school_contacts, through: :school_contact_emails, class_name: 'School::Contact'
end

如果我要查找电子邮件

s = School::Contact.first
=> #<School::Contact id: 1, name: "Headmaster Name", surname: "Headmaster Surname", school_contact_role_id: 1, school_id: 2285, created_at: "2018-06-24 17:47:21", updated_at: "2018-06-24 17:47:21", creator_id: 1, updater_id: 1>

它说school_contact_emails.contact_id不存在，但是表列应该是“ school_contact_id”

这是School :: Contact :: Email表的迁移

s.emails
Traceback (most recent call last):
ActiveRecord::StatementInvalid (PG::UndefinedColumn: ERROR:  column school_contact_emails.contact_id does not exist)

任何类型的帮助将不胜感激

Answer 1

您与此非常接近-Rails实际上希望外键反映关联对象的类名+ _id（在这种情况下为contact_id），而不是使用关联名本身（在这种情况下为school_contact）。

这在这里提供了两个选项：您可以重命名数据库中的列，也可以将foreign_key选项添加到关联中。

例如：

class School::Contact::Email < ApplicationRecord
  belongs_to :school_contact, class_name: 'School::Contact', foreign_key: 'school_contact_id'
  belongs_to :email, class_name: '::Email'
end

希望有帮助-如果您有任何疑问，请告诉我您如何上车和喊叫。

Rails通过缺少列为has_many命名空间

1 个答案: