手把手教你基于koa2，mongoose实现增删改查

初始化项目

npm init -y

先安装一波乱七八糟的依赖插件（需要具备一定的koa2知识，至于mongoDB自行百度安装教程）,模板引擎我使用的是art-template（据说是性能最好的，而且是因为JQ时代的产物，念旧）

npm i koa koa-router koa-bodyparser koa-static koa-views art-template koa-art-template mongoose  -S

安装nodemon实时监听修改

npm i nodemon -D

新建app.js入口文件，撸一把基础代码

const Koa = require('koa')

const app = new Koa()

const views = require('koa-views')

const bodyParser = require('koa-bodyparser')

// const Router = require('koa-router')

const path = require('path')

// const router = new Router()

const {connect} = require('./dbs/init.js')  //导入mongodb数据库

const {createUser} = require('./controller/users.js')

// 模板引擎

const render = require('koa-art-template');

render(app, {

  root: path.join(__dirname, 'views'),

  extname: '.html',

  debug: process.env.NODE_ENV !== 'production'

});

//自执行函数，链接数据库

;(async ()=>{

  await connect()

})()

const userRouter = require('./controller/users.js')

app.use(userRouter.routes(),userRouter.allowedMethods())

// app.use(router.routes(),router.allowedMethods())

app

  .use(bodyParser({enableTypes:['json', 'form', 'text']}))

  .use(require('koa-static')(__dirname + '/public'))

  .use(views(__dirname + '/views', {

    extension: 'html'

  }))

app.listen(4000,()=>{

  console.log('listen at port localhost:4000 ');

})

新建dbs文件夹，在下面统一管理数据库相关，新建init.js数据库初始化

const mongoose = require('mongoose')

const db = 'mongodb://localhost/mongo_test'; //link

// const glob = require('glob')

// const {resolve} = require('path')

// exports.initSchemas = ()=>{

//   // glob.sync(resolve(__dirname,'./schema','**/*.js')).forEach(require)

// }

// 连接数据库，URL以mongodb:// + [用户名:密码@] +数据库地址[:端口] + 数据库名。（默认端口27017）

// 连接mongodb数据库的链接解析器会在未来移除，要使用新的解析器，通过配置{ useNewUrlParser:true }来连接 ；其他警告参考：https://mongoosejs.com/docs/deprecations.html

/**

 * mongoose从@5.2.8后会弃用一些指令，为防止程序如下警告：

 * (node:24864) DeprecationWarning: collection.ensureIndex is deprecated. Use createIndexes instead.

 * (node:24841) DeprecationWarning: current URL string parser is deprecated, and will be removed in a future version. To use the new parser, pass option { useNewUrlParser: true } to MongoClient.connect.

 * 可以如下设置

 */

mongoose.set('useNewUrlParser', true)

mongoose.set('useFindAndModify', false)

mongoose.set('useCreateIndex', true)

let dbc = mongoose.connection

exports.connect = ()=> {

  // 链接数据库

  mongoose.connect(db)

  let  maxConnectTimes = 0

  return new Promise((resolve,reject)=>{

    // 增加数据库监听事件:断开链接

    dbc.on('disconnected',()=>{

      console.log('***********数据库断开***********')

      if(maxConnectTimes<=3){

        maxConnectTimes++

        mongoose.connect(db)

      }

      else {

        reject()

        throw new Error('数据库出现问题，请人为修理.....')

      }

    })

    dbc.on('error',err=>{

      console.log('***********数据库出错***********')

      if(maxConnectTimes<=3){

        maxConnectTimes++

        mongoose.connect(db)

      }

      else {

        reject()

        throw new Error('数据库出现问题，请人为修理.....')

      }

    })

    dbc.once('open',()=>{

      console.log('MongoDB Connected successfully!')

      resolve()

    })

  })

}

在dbs文件夹下新建schema文件夹用于创建各种schema表，新建Users.js

const mongoose = require('mongoose');

const Schema = mongoose.Schema;

let ObjectId = Schema.Types.ObjectId;

const userSchema = new Schema({

  UserId : {type:ObjectId},

  userName:{unique:true,type:String},//unique表示索引唯一

  password:String,

  gender:Number,

  userStatus:Number,

  createAt:{type:Date,default:Date.now()},

  lastLoginAt:{type:Date,default:Date.now()}

},{collection:'users'})

const model = {

  Users:mongoose.model('Users',userSchema)

}

// 发布模型

module.exports = model

新建controller文件夹，主要是用来处理一些业务逻辑，新建users.js文件

let {

  addUser,

  updateUser,

  delUser,

  findAllUsers,

  findOne

} = require('./tools.js');

const common = require("../libs/common");

const Users = require('../dbs/schema/Users.js').Users

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

let router = new Router()

router.prefix('/user')

// 查找列表

router.get('/list',async (ctx)=>{

  let code = 0 // 状态码

  let msg = '' // 返回内容

  let {keyword} = ctx.query ;

  let params = {

    keyword

  }

  let ret = await findAllUsers(params)

  ctx.body = {

    code,

    list:ret,

    msg:'操作成功'

  }

})

// 查找信息

router.get('/detail',async (ctx)=>{

  let code = 0 // 状态码

  let msg = '' // 返回内容

  let {id} = ctx.query ;

  let params = {

    id

  }

  let ret = await findOne(params)

  ctx.body = {

    code,

    list:ret,

    msg:'操作成功'

  }

})

router.post('/addUser',async (ctx)=>{

  let code = 0 // 状态码

  let msg = '' // 返回内容

  let {userName,password,gender,type,id} = ctx.request.body ;

  if(type=='edit'){

    if(id){

      let ret = await updateUser(ctx.request.body)

      if(ret.ok==1){

        code = 0

        msg = '修改成功'

      }

      else {

        code = -1

        msg = '修改失败,'

      }

    }

    else{

      code = -1

      msg = '参数错误,'

    }

  }

  // 删除

  else {

    // let id = common.uuid();

    let user = new Users({

      userName,

      password,

      gender,

      userStatus:1

    })

    try {

      let ret = await addUser(user)

      console.log(ret);

      code = 0

      msg = '添加成功'

    } catch (error) {

      code = -1

      msg = '新建失败'

    }

  }

  ctx.body = {

    code,

    msg

  }

})

router.post('/del',async (ctx)=>{

  let code = 0 // 状态码

  let msg = '' // 返回内容

  let ret = await delUser(ctx.request.body)

  console.log(ret);

  if(ret){

    ctx.body = {

      code,

      msg:'删除成功'

    }

  }

  else {

    ctx.body = {

      code:-1,

      msg:'参数错误'

    }

  }

})

module.exports = router

在当前controller目录下新建增删改查工具方法，tools.js

// 导入schama

const Users = require('../dbs/schema/Users.js').Users

/* 查所有用户 */

exports.findAllUsers = async (params) => {

  let keyword = params.keyword ||'' ;

  const reg = new RegExp(keyword, 'i') //不区分大小写

  // 模糊查询

  let _filter = {

    userStatus:1,

    $or:[

      {

        userName:{$regex :reg}

      }

    ]

  }

  let count = 0

  count = await Users.countDocuments(_filter)

  let ret = await Users.find(_filter).limit(20)

  let _list = ret.map(v=>{

    return {

      username:v.userName,

      gender:v.gender,

      createAt:v.createAt,

      lastLoginAt:v.lastLoginAt,

    }

  })

  return {

    count,

    list:_list

  }

};

/* 查单个用户 */

exports.findOne = async (params) => {

  let ret = await Users.findOne({_id:params.id})

  let info = {

    id:ret._id,

    userName:ret.userName,

    createAt:ret.createAt,

    lastLoginAt:ret.lastLoginAt,

    gender:ret.gender

  }

  return {

    info

  }

};

/* 新增用户 */

exports.addUser = async (userParams) => {

  console.log('add=');

  console.log(userParams);

  return await userParams.save();

};

/**

 * 编辑

 */

exports.updateUser = async (userParams)=>{

  console.log('edit=');

  console.log(userParams);

  return await Users.updateOne({_id:userParams.id},{

    $set:{

      userName:userParams.userName,

      password:userParams.password,

      gender:userParams.gender

    }

  })

}

/**

 * 硬删除

 */

exports.removeUser = async (userParams)=>{

  return await Users.findOneAndRemove({_id:userParams.id})

}

/**

 * 软删除

 */

exports.delUser = async (userParams)=>{

  return await Users.findOneAndUpdate({_id:userParams.id},{userStatus:0})

}

运行代码：配置package.json，scripts新增"dev": "nodemon node ./app.js"

运行：npm run dev

loacahost:4000/user/list获取列表

loacahost:4000/user/detail获取用户详情

loacahost:4000/user/addUser新增用户

loacahost:4000/user/del删除用户

手把手教你基于koa2，mongoose实现增删改查的相关教程结束。