anchor.diff:      data[index] = stu;
       i++;
     });
  -
  -  String jsonData = JSON.encode(data);
  -
  -  return jsonData;
  -}
  +  Future<String> getDataFromDb1() async {
  +      var results = await pool.query('select teaname,teaid from tealogin');
  +      int i = 0;
  +      results.forEach((row) {
  +        //列出所有用户名
  +        String index1 = "teaname" + i.toString();
  +        value1["teaname"]=row.teaname;
  +        value1["teaid"]=row.teaid;
  +        data1[index] = JSON.encode(value1);
  +        i++;
  +      });
  +      String jsonData = JSON.encode(data1);
  +      return jsonData;
  +    }
   
   
   
  
positive.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> _echoRequest(shelf.Request request) async {
    //接受post过来的数据
  
negative.code: 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',
  