    # File lib/active_record/connection_adapters/abstract/schema_definitions.rb, line 476
          def column(name, type, options = {})
            column = self[name] || ColumnDefinition.new(@base, name, type)
            if options[:limit]
              column.limit = options[:limit]
            elsif native[type.to_sym].is_a?(Hash)
              column.limit = native[type.to_sym][:limit]
            end
            column.precision = options[:precision]
            column.scale = options[:scale]
            column.default = options[:default]
            column.null = options[:null]
            @columns << column unless @columns.include? column
            self
          end