1. 下载mysql模块
   npm install mysql --save
2. 创建mysql连接池(connect.js文件）

const mysql = require('mysql');

var mysqlConnect = {};

var pool = mysql.createPool({
    connectLimit:10,
    host: "localhost",
    port: "3306",
    user: "root",
    password: "root",
    database: "2017final"
});

mysqlConnect.sql=function (query,callback) {
    if(!query){
        callback();
        return;
    }
    pool.query(query,function (err,rows,fields) {
       if(err){
           callback(err,null);
           return;
       }
       callback(null,rows,fields);
    });
};

module.exports = mysqlConnect;

3. 测试连接(select.js)

var mysqlConnect = require('./connect');

var selectQuery= "select * from users";
mysqlConnect.sql(selectQuery,function (err,rows,fields) {
    if(err){
        console.log(err);
        return;
    }
    console.log(JSON.stringify(rows));
});