1.当我所有代码搞好，运行后登陆不进去，我将main.js里的第31行最后一个词'production'改成‘development'后成功进入页面。
2.当我进去页面后，数据库可以创建不能删除，这时我把另一个文件里的app.js替换成了以下代码，问题成功解决。
const router = require('koa-router')()
//建立模块，require(“../db/models/文件名”)
let Model = require("../db/models/school");
router.prefix('/school')
router.get('/', function (ctx, next) {
ctx.body = 'this is a users response!'
})
//数据库增删改查
router.post('/add', async function (ctx, next) {
console.log(ctx.request.body)
let model = new Model(ctx.request.body);
model = await model.save();
console.log('user',model)
ctx.body = model
})
router.post('/find', async function (ctx, next) {
let models = await Model.
find({})
ctx.body = models
})
router.post('/get', async function (ctx, next) {
// let users = await User.
// find({})
console.log(ctx.request.body)
let model = await Model.find(ctx.request.body)
console.log(model)
ctx.body = model
})
router.post('/update', async function (ctx, next) {
console.log(ctx.request.body)
let pbj = await Model.update({ _id: ctx.request.body._id }, ctx.request.body);
ctx.body = pbj
})
router.post('/delete', async function (ctx, next) {
console.log(ctx.request.body)
await Model.remove({ _id: ctx.request.body._id });
ctx.body = 'shibai '
})
module.exports = router
