rename_column_sql

# File activerecord/lib/active_record/connection_adapters/abstract_mysql_adapter.rb, line 765
      def rename_column_sql(table_name, column_name, new_column_name)
        column  = column_for(table_name, column_name)
        options = {
          default: column.default,
          null: column.null,
          auto_increment: column.auto_increment?
        }

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