//连接数据库var mysql = require('mysql');var connection = mysql.createConnection({    host: 'bdm253137448.my3w.com', //数据库地址    user: 'bdm253137448',   //数据库用户名    password: 'muchengfeng123', //数据库管理密码    database:'bdm253137448_db', //数据库名称    insecureAuth: true  });connection.connect(function(err) {  if (err) {    console.error('error connecting: ' + err.stack);    return;  }   console.log('connected as id ' + connection.threadId);});var userModSql = 'UPDATE userinfo SET username = ?,pwd = ? WHERE id = 1';var userModSql_Params = ['Hello World',99];//改 upconnection.query(userModSql,userModSql_Params,function (err, result) {   if(err){         console.log('[UPDATE ERROR] - ',err.message);         return;   }         console.log('----------UPDATE-------------');  console.log('UPDATE affectedRows',result.affectedRows);  console.log('******************************');});//关闭连接connection.end();