Question

我目前有以下列ID，名称，电子邮件，linkedin，公司，联系方式，招聘人员，学生，并且我想添加一个称为“已响应”的新列。我只找到有关如何向数据库中所有现有实例添加新列的答案。所以我确实尝试了这个：

db.people.update({}, {$set: {"responded": false}}, false, true)

我所有现有的实例都有一个字段：responded默认情况下设置为false。现在，当我尝试添加新人时，出现此错误：

Mongoid::Errors::UnknownAttribute in PeopleController#create



 message: Attempted to set a value for 'responded' which is not allowed on the model Person. summary: Without including Mongoid::Attributes::Dynamic in your model and the attribute does not already exist in the attributes hash, attempting to call Person#responded= for it is not allowed. This is also triggered by passing the attribute to any method that accepts an attributes hash, and is raised instead of getting a NoMethodError. resolution: You can include Mongoid::Attributes::Dynamic if you expect to be writing values for undefined fields often.

Answer 1

MongoDB没有“列”，也没有表。您的文档带有字段。

我想您正在为模型使用MongoID，因此只需要在模型上定义字段

class Person
  include Mongoid::Document
  field :first_name, type: String
  field :middle_name, type: String
  field :last_name, type: String
  field :responded, type: Boolean # something like this
end

https://docs.mongodb.com/mongoid/current/tutorials/mongoid-documents/#fields

如何在Rails Mongodb中添加新列？

1 个答案: