anchor.diff:  import 'dart:convert' show JSON;
   import '../lib/stu_class.dart';
   
  +
   Map<String, String> data = new Map();
   Map<String, String> value = new Map();
  +Map<String, String> data1 = new Map();
  +Map<String, String> value1 = new Map();
  +
   final pool = new ConnectionPool(host: "localhost",
       port: 3306,
       user: 'suzyfish',
  
positive.code:     data[index] = stu;
      i++;
    });
  
    String jsonData = JSON.encode(data);
  
    return jsonData;
  }
  
  
  
  
negative.code:   //把这个post过来的数据有返回给客户端
    return new shelf.Response.ok('${userName}'    );
  }
    Future<shelf.Response> forteaid(shelf.Request request) async {
        //从数据库获取数据
        String userName1 = await getDataFromDb1();
  
        //把这个post过来的数据有返回给客户端
        return new shelf.Response.ok(
            ' ${userName1}'
        );
      }
  
  /*Future<shelf.Response> _echoRequest(shelf.Request request) async {
    //接受post过来的数据
  