1. 环境node v7.6版本以上

2. 创建服务安装依赖

新建文件夹

mkdir koa && cd koa

初始化

node init -y

安装依赖

node i koa --save

node i @koa/router --save

node i koa-bodyparser --save

node i mysql --save

3. 根目录新建index.js，新建router.js，controller文件夹

index.js

'use strict'
const Koa = require('koa')
const app = new Koa()

const bodyParser = require('koa-bodyparser')
const router = require("./router")
app.use(bodyParser())
app.use(router.routes())

app.use((ctx) => {
    ctx.body = 'Hello koa'
})

app.listen(10021, () => {
    console.log('服务已启动~')
})

router.js

'use strict'
const Router = require("@koa/router")
const router = new Router()
const serverController = require("./controller/server")

router.get("/getFirstFun", serverController.test)

module.exports = router

controller文件夹下新建server.js

'use strict'

class serverController {
    static async test(ctx) {
        ctx.body = "第一个接口"
    }
}
module.exports = serverController

4. 浏览器访问

127.0.0.1:10021/getFirstFun

5. 连接mysql

根目录新建config.js做配置文件
config.js

let config = {
    Dbs: {
        host: '127.0.0.1',
        user: 'root',
        password: 'root',
        database: 'mydb'
    }
}
module.exports = config

根目录新建mysql.js

'use strict'
const mysql = require("mysql")
const {Dbs} = require('./config')

const pool = mysql.createPool({
    host: Dbs.host,
    user: Dbs.user,
    password: Dbs.password,
    database: Dbs.database
})

function Query(sql, values) {
    return new Promise((resolve, reject) => {
        pool.getConnection(function (err, connection) {
            if (err) {
                reject(err)
                resolve({msg: "连接失败", err})
            } else {
                connection.query(sql, values, (err, rows) => {
                    if (err) {
                        reject(err)
                        resolve({msg: "查询失败", err})
                    } else {
                        resolve(rows)
                        connection.release() //释放连接池

                    }
                })
            }
        })
    })
}

module.exports = {Query}

6. 查询测试

server.js引入mysql

const mysql = require('../mysql')

let sql = `select * from file limit 1`
let result = await mysql.Query(sql)
ctx.body = result

7、其它

其它数据连接参考：https://www.cnblogs.com/joyo-w/p/10660952.html

代码：https://gitee.com/niceguy802/koa.js-server.git