Base Database Module

base.rb

require "singleton"

module SIA
  # Singleton class to enable database access for those occasions where a model will just not do.
  # @author Ciaran Archer
  class Database
    include Singleton
    @databases = nil

    # Setup database connections with configuration file.
    # @author Ciaran Archer
    # @param [String] config @todo this may have to be adjusted to cater for multiple database hosts
    # @return self
    def setup(config)
      raise ArgumentError, "database_config is required" unless config.is_a? Hash

      @databases = {
        :sia => Sequel.connect("jdbc:jtds:sqlserver://#{config[:host]}/SIA;user=#{config[:username]};password=#{config[:password]}"),
        :br => Sequel.connect("jdbc:jtds:sqlserver://#{config[:host]}/BR;user=#{config[:username]};password=#{config[:password]}")
      }

      self
    end

    # Return a set of database connections as a hash indexed by database name.
    # @author Ciaran Archer
    # @return Hash
    # @raise [LoadError] if the database has not been configured.
    def databases
      raise LoadError, "database has not been configured" unless @databases.is_a? Hash
      @databases
    end
  end
end

clients.rb

module SIA
  module SIAModels

    @sia_db = SIA::Database.instance.databases[:sia]

    # Model to represent the Clients table.
    # @author Ciaran Archer
    class Client < Sequel::Model(@sia_db[:clients])
      set_primary_key [:clientid]

      def self.get_all
        dataset.filter("clientid > 0")
      end
    end
  end
end

routes.rb

    get "/all" do

      total_time = Benchmark.realtime do
        results = SIA::SIAModels::Client.get_all

        results.each do |c|
          puts c[:firstname]
        end
      end

      puts "done in #{total_time}"
      "done in #{total_time}"

    end