Flutter 问题：在真实设备上运行时，与 postgresql 数据库的连接不起作用

Question

I got a problem when running my flutter app on my phone while connecting with postgresql database and the terminal is not showing any error. PS: when I run the app on an emulator it's working fine. any help please??

signIn(String username, password) async {
    SharedPreferences.setMockInitialValues({});
    SharedPreferences sharedPreferences = await SharedPreferences.getInstance();

    Map data = {
      'username': username,
      'password': password
    };
    var ur = Uri.parse('http://192.168.137.5:8000/api/token/auth/'); 
    var jsonResponse;
    var response = await http.post(ur, body: data);
    print(response.body);
    var user = response.body;
    if(response.statusCode == 200) {

      jsonResponse = json.decode(response.body);
      
      if(jsonResponse != null) {
        setState(() {
          _isLoading = false;
        });
        
        sharedPreferences.setString("token", jsonResponse['token']);
        sharedPreferences.setString("username", jsonResponse['username']);
        sharedPreferences.setInt("user_id", jsonResponse['user_id']);
        int id =sharedPreferences.getInt('user_id');
        
        final connection = PostgreSQLConnection("192.168.137.5", 5432, "aaa", username: "aaaa", password: "aaa");
        
        
        await connection.open();
        print('connected');
        var result = await
        connection.query("SELECT * FROM public.employee_employee, public.auth_user where public.employee_employee.user_id= ${id}");

        print(result);
        
        sharedPreferences.setString("nom", result[0][7]);
        Navigator.of(context).pushAndRemoveUntil(MaterialPageRoute(builder: (BuildContext context) => Home()), (Route<dynamic> route) => false);
       await connection.close();
      }
    }
    else {
      setState(() {
        _isLoading = false;
      });
      print(response.body.characters);
    }
  }

Answer 1

It is just because your phone and laptop are not connected with same connection or you can run your app on emulator instead of real device or you can push your code on testing server like heroku then it will work perfectly.