koa项目初始化

1.安装

npm init
npm i koa koa-static koa-router mysql co-mysql

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目录结构:

image.png

2.server.js

const Koa = require('koa')
const Router = require('koa-router')
const mysql = require('mysql')
const co = require('co-mysql')

let conn = mysql.createPool({ host: 'localhost', user: 'root', password: '123456', database: 'oj' })

let server = new Koa()
let router = new Router()
server.listen(8088)

server.context.db = co(conn)
server.use(async (ctx, next) => {
    ctx.set('Access-Control-Allow-Origin', '*')

    await next()
})
router.use('/api', require('./routers/api'))

server.use(router.routes())

3.index.js

const Router = require('koa-router')

let router = new Router()

router.get('/problem', async ctx => {
    ctx.body = await ctx.db.query('SELECT * FROM problem')
})

module.exports = router.routes()