rename_column_sql

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 687
      def rename_column_sql(table_name, column_name, new_column_name)
        options = { name: new_column_name }

        if column = columns(table_name).find { |c| c.name == column_name.to_s }
          options[:default] = column.default
          options[:null] = column.null
          options[:auto_increment] = (column.extra == "auto_increment")
        else
          raise ActiveRecordError, "No such column: #{table_name}.#{column_name}"
        end

        current_type = select_one("SHOW COLUMNS FROM #{quote_table_name(table_name)} LIKE '#{column_name}'", 'SCHEMA')["Type"]
        schema_creation.accept ChangeColumnDefinition.new column, current_type, options
      end