var mysql = require(‘mysql‘);var conn = mysql.createConnection({    host: ‘localhost‘,    user: ‘root‘,    password: ‘‘,    database:‘nodejs‘,    port: 3306});conn.connect();//查询// conn.query(‘SELECT * from user where name="wangzhiwei"‘, function(err, result) {//     if (err) throw err;//     console.log(result);// })//新增// conn.query(‘insert into user (username,password) values("huxiaona","123456")‘, function(err, result) {//     if (err) throw err;//     console.log(result);// })//删除// conn.query(‘delete from user where username="wupeigui"‘, function(err, result) {//     if (err) throw err;//     console.log(result);// })conn.query(‘update user set id="1" where username="huxiaona"‘,function(err,result){    if (err) {throw err};    console.log("修改数据成功");})conn.end();