How to properly send data in json to node.js client?

Question

Node.js

Hello everyone, I have a question. I want to update the news feed on socket.io, but the question arose of how to give it all in json format? and which is better to use pool or static sql?
here is server.js code

var io = require('socket.io').listen(3000),
  mysql = require('mysql');

var pool  = mysql.createPool({
  	host            : 'localhost',
  	user            : 'root',
  	password        : '',
  	database        : 'test',
  port			: 3306
});
// Навешиваем обработчик на подключение нового клиента
io.sockets.on('connection', function (socket) {
  var time = (new Date).toLocaleTimeString();
  // Посылаем клиенту сообщение о том, что он успешно подключился
  socket.json.send({'event': 'connected', 'time': time});
  setInterval(function() {
    socket.broadcast.json.send(updateFeed());
  }, 5000);
});
function updateFeed() {
  pool.getConnection(function(err, connection) {
    connection.query('SELECT `u`.`member`, `u`.`login`, `n`.`text`, `n`.`time` FROM `news` as `n` LEFT JOIN `members` as `u` ON (`u`.`member` = `n`.`member_id`) ORDER BY `n`.`n_id` DESC LIMIT 0, 5', function(err, rows) {
      var gdata = "";
      [rows].forEach(function(item, key, rows){
        for(var index in item)
        {
if(item.hasOwnProperty(index)) {
          gdata += {
            index: item[index]
          };
}
        }
      });
      return gdata;
      connection.release();
      });
  });
};

and client code

socket = io.connect('localhost:3000');

    socket.on('connect', function () {
        socket.on('message', function (msg) {
            console.log(msg);
    });
  });

the matter is that it gives me null. What am I doing wrong?

Answer 1

var gdata = "";
gdata += { add an object to the line??? gets a line
index: item[index]
};
socket.broadcast.json.send(updateFeed() returns a string, expects an object);

Answer 2

Mixing asynchronous functions with synchronous ones.
updateFeed will not return anything, because it will finish before the asynchronous functions in it.