var express = require('express');var app = express();var mysql = require('mysql');var connection = mysql.createConnection({ host : 'localhost', user : 'root', password : 'root', port : 3306, database : 'test'})sql = 'select * from websites';var arr = [];connection.query(sql,function (err, results) { if (err){  console.log(err) }else{  console.log(results);  for(var i = 0;i < results.length;i++){   arr[i] = results[i].name;  }  app.get('/',function (req, res) {   res.send(arr); //這里必須用res.send,因為有數據返回到客戶端  }) }})app.listen(3001);