首先安装express

$ cnpm install express --save

然后贴代码

var express = require('express');
var app = express();
var mysql = require('mysql');
//获取post下参数
var bodyParser = require('body-parser')
app.use(bodyParser.urlencoded({ extended: false }))
app.use(bodyParser.json())
//数据库配置
var connection = mysql.createConnection({
    host: 'localhost',
    user: 'root',
    password: 'zxc123',
    database: 'test'
});
//连接数据库
connection.connect();
//允许所有跨域请求
app.all("*", function (req, res, next) {
    res.header("Access-Control-Allow-Origin", "*");          
    next();
})
//注册方法
function registered(username, password,res) {
    var sql = 'INSERT INTO test (username,password) VALUES(?,?)';
    var sqlParams = [username, password]
    connection.query(sql, sqlParams, function (err, result) {
        if (err) {
            console.log('[SELECT ERROR] - ', err.message);
            return;
        } else {
            res.send({ code: 200 });
        }
    });
}
//登录方法
function login(username, password,res) {
    var sql = 'SELECT * FROM test where username = ? and password = ?';
    var sqlParams = [username, password]
    //查
    connection.query(sql, sqlParams, function (err, result) {
        if (err) {
            console.log('[SELECT ERROR] - ', err.message);
            return;
        }
        if (result.length == 0) {
            res.send({ mag: "没有数据" });
        } else {
            res.send(JSON.stringify(result));
        }
    });
}
app.post('/registered', function (req, res) {
    registered(req.body.username, req.body.password,res);
})
app.post('/login', function (req, res) {
    login(req.body.username, req.body.password,res);
})
//设置服务端口
var server = app.listen(8081)

最后node xxx.js运行node服务
如果是在宝塔面板里使用pm2管理器的话 记得一定要先运行一下 不然可能找不到端口号,顺便一提,记得开放端口号