使用Mongoose對MongoDB進行操作

const mongoose = require('mongoose'); mongoose.connect('mongodb://localhost/test',{ })

Mongoose中的Schema

• 定義Schema categorySchema

const categorySchema = new mongoose.Schema({name:String,description: String,createdAt:{type: Date,default: Date.now} });

• 通過model方法獲得該模型

const Category = mongoose.model('Category', categorySchema);

• 實例化一個新的對象來新增數據

const category = new Category({name: 'test',description: 'test category' });

• 通過save方法,保持對象到數據庫中

category.save(err=>{if(err){console.error(err);return}console.log('saved'); })

• 直接通過模型的Create方法

Category.create({name:'test',description: 'test category' }, (err, category)=>{if(err){console.error(err);} else {console.log(category)} });

• 通過find方法,查詢name='test’的結果

Category.find({name:'test' }, (err, res) =>{if(err){console.error(err)} else{console.log(res);} });

• 刪除數據

Category.remove({name:'test' }).then(()=>{ })

• 更新數據

Category.update({name:'test' },{name:'test1',description: 'test1' }).thenm(()=>{})

栗子

• 目錄結構如下
  

• 說明:
  course.js:定義了Course表的結構
  coon.js:連接數據庫
  db.js:接口的封裝
  app.js:負責路由處理和基本的koa相關的配置

• /mongoDB/model/course.js

const mongoose = require('mongoose'); const timeRangeSchema = new mongoose.Schema({hour: {type: Number,max: 24,min: 8},minute: {type: Number,max: 59,min: 0},time: {type: Number,get() {return this.get('hour') * 100 + this.get('minute');}} });const courseSchema = new mongoose.Schema({name: String,startTime: timeRangeSchema,endTime: timeRangeSchema }) const Course = mongoose.model('Course', courseSchema);module.exports = Course;

• db.js

const Course = require('./model/course');const getCourseList = async () => {return await Course.find({}).sort({'startTime.time': 1}); }const getCourseById = async (id) => {return await Course.findById(id); }const getCourseByTime = async (start, end, weekday) => {return await Course.find({weekday: weekday}).where('startTime.time').gte(start.hour * 100 + start.minute).where('endTime.time').lte(end.hour * 100 + end.minute); } const addCourse = async (course) => {const { name, weekday, startTime, endTime } = course;const item = await getCourseByTime(startTime, endTime, weekday);if (item) {throw new Error('當前時間段已經安排了課程');}return await Course.create(course); }const updateCourse = async (id, course) => {return await Course.update({_id: id}, course); }const removeCourse = async (id) => {return await Course.remove({_id: id}); }module.exports = {getCourseList,getCourseById,addCourse,updateCourse,removeCourse }

• conn.js

const mongoose = require('mongoose');const connect = async () => {await mongoose.connect('mongodb://localhost/course', {useNewUrlParser: true,useUnifiedTopology: true}); }const close = async () => {await mongoose.connection.close(); }module.exports = { connect, close }

• app.js

const koa = require('koa'); const app = new koa(); const router = new require('koa-router')(); const bodyParser = require('koa-bodyparser'); const {getCourseList,getCourseById,addCourse,updateCourse,removeCourse } = require('./db');const {connect,close } = require('./conn');const JSON_MIME = 'application/json';router.get('/course', async ctx => {ctx.type = JSON_MIME;ctx.body = {status: 0,data: await getCourseList()} });router.get('/course/:id', async ctx => {ctx.type = JSON_MIME;ctx.body = {status: 0,data: await getCourseById(ctx.params.id)} });router.post('/course', async ctx => {ctx.type = JSON_MIME;await addCourse(ctx.body);ctx.body = {status: 0} });router.put('/course/:id', async ctx => {await updateCourse(ctx.params.id, ctx.body);ctx.body = {status: 0} });router.delete('/course/:id', async ctx => {await removeCourse(ctx.params.id);ctx.body = {status: 0} })app.use(async (ctx, next) => {await connect()await next()await close() })app.use(bodyParser()); app.use(router.routes()); app.listen(3000, async () => {console.log('Server is running at http://localhost:3000'); })

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