首先，MongoDB和PostgreSQL都有好有坏，这取决于你需要的功能类型，请参见：https://www.geeksforgeeks.org/difference-between-postgresql-and-mongodb/
关于Phantom自定义字段类型，这确实与ActiveRecord::Enum做了相同的事情，但需要编写更多的代码。您能分享一下您为测试运行的不工作的代码吗？

编辑日期：2022年2月7日

下面是一个例子，你可以在mongo中使用enum而不需要写太多代码：

module MongoEnum
  # Takes application-scope value and converts it to how it would be
  # stored in the database. Converts invalid values to nil.
  def mongoize(object)
    mapping[object]
  end

  # Get the value as it was stored in the database, and convert to
  # application-scope value. Converts invalid values to nil.
  def demongoize(object)
    inverse_mapping[object]
  end

  # Converts the object that was supplied to a criteria and converts it
  # into a query-friendly form. Returns invalid values as is.
  def evolve(object)
    mapping.fetch(object, object)
  end

  def mapping
    @mapping ||= self.const_get(:MAPPING).freeze
  end

  def inverse_mapping
    @inverse_mapping ||= mapping.invert.freeze
  end
end

class RoleEnum
  extend MongoEnum

  MAPPING = {
    'admin' => 0,
    'user' => 1,
  }.freeze
end

class ColorEnum
  extend MongoEnum

  MAPPING = {
    'black' => 0,
    'white' => 1,
  }.freeze
end

class Profile
  include Mongoid::Document
  field :color, type: ColorEnum
end

class User
  include Mongoid::Document
  field :role, type: RoleEnum
end

免责声明：我没有在一个真实的的应用程序中测试它，让我知道如果它不工作。