Mongoid: uninitialized constant (NameError)

Question

I'm currently trying to write a very basic portion of code that reads a ruby file and instantiate some documents into my local MongoDB.

The class modeling my Mongo document is in a separate file called 'search_term.rb', as follows:

class SearchTerm
  include Mongoid::Document
  field :search_term, type: String
end

In a separate file called 'populate_database.rb' that resides in the same folder as 'search_term.rb', I'm trying to read from a list and create new documents and look into my MongoDB Compass if they are actually being created:

require_relative 'search_term'

business_list = [
  'business name 1',
  'business name 2',
  'business name 3',
  'business name 4',
]

for business in business_list
  s_term = SearchTerm.new()
  s_term.search_term = business
  s_term.post
end

The problem is: when I run 'ruby populate_database.rb' I'm getting the error:

<class:SearchTerm>': uninitialized constant SearchTerm::Mongoid (NameError)

I have already tried creating an empty Gemfile and writing:

gem 'mongo'
gem 'mongoid'

into them and running 'bundle install'. After that the following Gemfile.lock file is created:

GEM
  specs:
    activemodel (6.1.4.1)
      activesupport (= 6.1.4.1)
    activesupport (6.1.4.1)
      concurrent-ruby (~> 1.0, >= 1.0.2)
      i18n (>= 1.6, < 2)
      minitest (>= 5.1)
      tzinfo (~> 2.0)
      zeitwerk (~> 2.3)
    bson (4.12.1)
    concurrent-ruby (1.1.9)
    i18n (1.8.10)
      concurrent-ruby (~> 1.0)
    minitest (5.14.4)
    mongo (2.13.0)
      bson (>= 4.8.2, < 5.0.0)
    mongoid (7.3.2)
      activemodel (>= 5.1, < 6.2)
      mongo (>= 2.10.5, < 3.0.0)
      ruby2_keywords (~> 0.0.5)
    ruby2_keywords (0.0.5)
    tzinfo (2.0.4)
      concurrent-ruby (~> 1.0)
    zeitwerk (2.4.2)

PLATFORMS
  x64-mingw32

DEPENDENCIES
  mongo
  mongoid

BUNDLED WITH
   2.2.27

But the problem still persists. Can you guys give me some advice on how to solve this one?

Thanks in advance!!

Answer 1

If you are not using Rails, you need to require "mongoid" yourself somewhere in your application and then load Mongoid configuration. See here for an example of how to do that.