Dynamically create ActiveRecord models (PostgreSQL example)

model_factory.rb

# How to dynamically create model classes in PostgreSQL and ActiveRecord?
require 'active_record'

class ModelFactory < ActiveRecord::Base
  self.abstract_class = true

  class << self
    def build_model(params)
      schema = params[:schema]
      table = params[:table]
      full_name = "#{schema}.#{table}"

      create_database_objects(schema, table, full_name)

      model = Class.new(ModelFactory) do
        self.table_name = full_name
      end

      model
    end

    private
    def create_database_objects(schema, table, full_name)
      connection = ModelFactory.connection

      # Create Schema 
      unless connection.schema_exists?(schema)
        begin
          connection.create_schema(schema)
        rescue PG::DuplicateSchema
        end
      end

      # Create Table
      new_table = false
      unless connection.table_exists?(full_name)
        new_table = true
        begin
          connection.create_table(model.table_name) do |table|
            table.column :name, :string, limit: 50, null: false
            table.column :address, :string, limit: 300, null: false
            table.column :timestamp, :integer, null: false
          end
        rescue PG::DuplicateTable
        end
      end

      # What's next? Maybe adding indexes, who knows, sky is the limit
    end
  end

end