Problem

InfindAddUsers.jsWhen you find () in, you can read the data normally, but there is no data when you return.

Code

findAddUsers.js

const mongoose = require('mongoose')
 
 let Schema = mongoose.Schema
 
 let UserSchema = new Schema({
 name: String,
 age: Number
 })
 
 let temp = mongoose.model('temp', UserSchema)
 
 exports.findAllUsers = async () => {
 let query = temp.find()
 
 let res = [1,2,3]
 
 await query.exec(function (err, users) {
 if (!  err) {
 res = users
 // console.log(res) // data can be printed here
 }
 })
 // console.log(res) // res here is empty and has no value
 return res
 }

app.js

const Koa = require('koa')
 const app = new Koa()
 
 const router = require('./router/router.js')
 
 const mongoose = require('mongoose')
 mongoose.connect('mongodb://localhost/db1')
 
 app
 .use(router.home.routes())
 .use(router.home.allowedMethods())
 
 app.listen(3000, () => {
 console.log('running')
 })

router.js

const Router = require('koa-router')
 const router = new Router()
 
 const controller = require('../controller/user.js')
 
 module.exports = {
 home: router.get('/', controller.getAllUsers)
 }

user.js

const userHelper = require('../dbhelp/findAllUsers.js')
 
 module.exports = {
 getAllUsers: async (ctx, next) => {
 ctx.body = await userHelper.findAllUsers()
 }
 }