Official document

https://docs.mongodb.com/ecosystem/tutorial/mongoid-installation/

Install & Setting Summary

gem 'mongoid'
gem 'mongoid', github: 'mongodb/mongoid' # rails5の場合まだreleaseされてないから

rails g mongoid:config
Running via Spring preloader in process 30471
      create  config/mongoid.yml

Field

• schemaless databaseだけど大半は定義して使ってるでしょう
• またfiledを指定するとideやfieldへのaccessがいい

class Person
  include Mongoid::Document
  field :first_name, type: String
  field :middle_name, type: String
  field :last_name, type: String
end

• Array
• BigDecimal
• Boolean
• Date
• DateTime
• Float
• Hash
  • field type Hashを使う場合には legal key names for mongoDBに違反してないように注意
• Integer
• BSON::ObjectId
• BSON::Binary
• Range
• Regexp
• String
• Symbol
• Time
• TimeWithZone

Accessing Field Values

# Get the value of the first_name field
person.first_name
person[:first_name]
person.read_attribute(:first_name)


# Set the value for the first_name field
person.first_name = "Jean"
person[:first_name] = "Jean"
person.write_attribute(:first_name, "Jean")

getter, setterを適用すると .を使う表現の値はtterに影響される

class Person
  include Mongoid::Document

  field :first_name

  # custom getter
  def first_name
    "My name is Johnny"
  end

  # custom setter
  def first_name=(value)
    p 'Setting.. '
    self.first_name = value
    p '.. done!'
  end
end

# Like this:
person.first_name = 'John'
# Setting..
# .. done!

person.first_name                  # My name is Johnny
person[:first_name]                # John
person.read_attribute(:first_name) # John

Hash field

# all data will fail to save due to the illegal hashkey
def set_vals_fail
  self.first_name = 'Daniel'
  self.url = {'home.page' => 'http://www.homepage.com'}
  save
end

Logging

Mongoid.logger.level = Logger::DEBUG
Mongo::Logger.logger.level = Logger::DEBUG