连接Mysql数据库

用Navicat管理工具，新建一个数据库，node_db

新建一张user表

使用WebStrom新建一个项目Node.js，在此目录下新建demo01，再新建一个包命名为db

在db包下新建db.js文件，用来连接数据库

//导入依赖
var mysql = require("mysql");
//创建数据库连接
var connection = mysql.createConnection({
    host:"127.0.0.1", //主机IP
    port:3306,        //端口号
    user:"root",	  //用户名
    password:"root",  //密码
    database:"node_db"   //数据库名
});
//启动连接
connection.connect();
//执行sql语句，查询两条
connection.query("select * from people limit 0,2 ",function(error,result,fields){
    if(error) throw error;
    console.log(result);
});

运行db.js

运行结果

说明：Node.js连接数据库成功！

TCP服务端

const net = require('net');

const server = new net.Server();

server.listen(9999, '127.0.0.1', () => {
    console.log(`server is listening on ${server.address().address}:${server.address().port}`);
})

server.on('connection', (socket) => {
    server.getConnections((err, connections) => {
        console.log('current client is:', connections);
    });

    socket.on('data', (data) => {
        console.log(`received data:${data.toString()}`);
    })
})

TCP客户端

const net = require('net');

const client = new net.Socket();

client.connect({
    port: 9999,
    address: '127.0.0.1',
})

client.on('connect', () => {
    console.log('connect success');

    client.write(`Hello Server!,I'm ${Math.round(Math.random() * 100)}`)
});