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: 'jol' })

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

server.context.db = co(conn)

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

    await next()
})

let router = new Router()

router.use('/api', require('./routers/api'))

server.use(router.routes())

index.js

const Router = require('koa-router')
const Sequelize = require('sequelize');

const sequelize = new Sequelize('jol', 'root', '123456', {
    host: 'localhost',
    dialect: 'mysql' ,
});

let router = new Router()

router.get('/problem', async ctx => {
    ctx.body = await ctx.db.query('SELECT * FROM problem')
})
 router.get('/problem/:id', async ctx => {
     let { id } = ctx.params
     ctx.body = await ctx.db.query('SELECT * FROM problem WHERE problem_id=?', [id])
 })
router.get('/catalog/:parent', async ctx => {
    let { parent } = ctx.params
    ctx.body = await ctx.db.query('SELECT ID, title FROM catalog_table WHERE parentID=?', [parent])
})

router.get('/problem/:id', async ctx => {
    let { id } = ctx.params
    ctx.body = await ctx.db.query('SELECT * FROM problem WHERE problem_id=?', [id])
})
module.exports = router.routes()