Node 连接池pool

//1:加载相应的模块 http url fs mysql
const http = require("http");
const url = require("url");
const fs = require("fs");
const mysql = require("mysql");
//2:创建连接池
var pool = mysql.createPool({
host:'127.0.0.1',
user:'root',
password:'',
database:'jd',
connectionLimit:5 //连接池大小
});
//3:创建服务器
var server = http.createServer();
server.listen(80);
//4:为服务器注册事件request
//参数 req 请求对象(客户信息)
//参数 res 响应对象(服务器信息)
server.on('request',(req,res)=>{
//5:解析参数
var objUrl = url.parse(req.url,true);
//6:获取请求地址
var path = objUrl.pathname;
//7:设置响应头信息格式
res.setHeader('content-type','text/html;charset=utf-8');
//8:判断路径
if(path==='/register'){
//9:异步读取文件
fs.readFile("./public/register.html",(err,data)=>{
if(err)throw err;
res.end(data);
});
}else if(path==='/register.do'){
var n = objUrl.query.uname;
var p = objUrl.query.upwd;
//10:从连接池中获取一个连接
pool.getConnection((err,conn)=>{
if(err){
console.log("从连接池中获取连接失败");
}else{
//11:发送sql语句
conn.query("INSERT INTO jd_user VALUES(null,?,?)",
[n,p],(err,result)=>{
if(err){
console.log("sql语句执行失败");
}else{
console.log("执行成功");
}
//12:释放连接
conn.release();
});
}
});

}

});

//4:解析参数如果请求 register 返回register.html
//5: register 添加数据库