gistfile1.rb

    def self.establish_connection(spec = nil)
      case spec
        when nil
          raise AdapterNotSpecified unless defined? RAILS_ENV
          establish_connection(RAILS_ENV)
        when ConnectionSpecification
          @@connection_handler.establish_connection(name, spec)
        when Symbol, String
          if configuration = configurations[spec.to_s] || configuration = configurations[Rails.env][spec.to_s]
            establish_connection(configuration)
          else
            raise AdapterNotSpecified, "#{spec} database is not configured"
          end
        else
          
          spec = spec['default'] ? spec['default'].symbolize_keys : spec.symbolize_keys
          unless spec.key?(:adapter) then raise AdapterNotSpecified, "database configuration does not specify adapter" end