node.js使用mongoose操作数据库实现购物车的增、删、改、查功能示例

goods.findOne({productId},(err,goodsDoc)=>{
   goodsDoc.productNum=1;
   goodsDoc.save(err,doc);
});

model.remove(conditions,callback(){})

model.update(conditions,updates,callback(){})

model.find(conditions,callback(){})

  addCart(productId){//加入购物车
   axios.post('./users/addCart',{
    userId:"100000077",
    productId:productId
   }).then((response)=>{
    let res=response.data;
    console.log(res.msg);
   });
  }

var express = require('express');
var router = express.Router();
const mongoose=require('mongoose');
var user=require('../models/userModel');
var goods=require('../models/productModel');
//连接数据库
mongoose.connect('mongodb://localhost:27017/mall');
mongoose.connection.on('connected',()=>{
 console.log("mongoDB连接成功");
});
//处理添加购物车请求
router.post('/addCart',(req,res,next)=>{
 let userId=req.body.userId;
 let productId=req.body.productId;
 let params={
  userId
 };
 user.findOne(params,(err,userDoc)=>{//查询对应用户信息
  if (err){
   res.json({
    status:1,
    msg:err.message
   });
  }else{
   if(userDoc){
    let inCart=false;
    userDoc.cartList.forEach(function(item){//遍历cartList比对商品id
     if (item.productId==productId){    //若商品在购物车内，数量增加
      inCart=true;
      item.productNum++;
      saveDoc(userDoc,res);
     }
    });
    //所选商品不在购物车内，则从商品列表内查找并添加到购物车
    if(!inCart){
     goods.findOne({productId},(err,goodsDoc)=>{
      if(err){
       res.json({
        status:1,
        msg:err.message
       })
      }else{
       goodsDoc.checked=true;
       goodsDoc.productNum=1;
       userDoc.cartList.push(goodsDoc);//将商品插入到用户cartList数组内
       console.log(userDoc.cartList);
       saveDoc(userDoc,res);
      }
     });
    }
   }
  }
 })
});

function saveDoc(doc,res) {
 //保存操作
 doc.save((err,doc)=>{
  if (err){
   res.json({
    status:1,
    msg:err.message
   })
  }else {
   res.json({
    status:0,
    msg:"添加购物车成功",
    result:'success'
   })
  }
 })
}

   deleteCart(){
    axios.post('users/deleteCart',{
     productId:this.productId
    }).then((response,err)=>{
     let res=response.data;
     if(res.status===0){
      this.getCart();
      this.modalShow=false;
     }
    })
   },

router.post('/deleteCart',(req,res)=>{
 "use strict";
 let productId=req.body.productId;
 let userId=req.cookies.userId;
 user.update({userId:userId},{
  $pull:{
   cartList:{productId:productId}
  }
 },(err,doc)=>{
  if(err){
   res.json({
    status:1,
    msg:'数据库删除失败'
   })
  }else{
   if(doc){
    res.json({
     status:0,
     msg:'购物车删除成功'
    })
   }
  }
 })
});

editCart(flag,item){
    if(flag==='check'){
     item.checked=!item.checked;
    }else if(flag==='add'){
     item.productNum++;
    }else if(flag==='sub'){
     item.productNum<=0 ? item.productNum=0 : item.productNum++ ;
    }
    axios.post('users/editCart',{
     productId:item.productId,
     checked:item.checked,
     productNum:item.productNum
    }).then((response,err)=>{
     let res=response.data;
     if(res.status===0){
      this.getCart();
     }else{
      console.log(res.msg);
     }
    })
}

router.post('/editCart',(req,res)=>{
 "use strict";
 let productId=req.body.productId;
 let checked=req.body.checked;
 let productNum=req.body.productNum;
 let userId=req.cookies.userId;
 user.update({userId:userId,'cartList.productId':productId},{
  $set:{"cartList.$.checked":checked,"cartList.$.productNum":productNum}
 },(err,doc)=>{
  if(err){
   res.json({
    status:1,
    msg:err.message
   })
  }else {
   res.json({
    status:0,
    msg:'购物车更新成功'
   })
  }
 })
});

   getCart(){
    axios.get('users/getCart').then((response,err)=>{
     let res=response.data;
     if(res.status===0){
      this.cartList=res.result.list;
     }else{
      console.log(res.msg);
     }
    })
   },

router.get('/getCart',(req,res)=>{
 "use strict";
 user.findOne({userId:req.cookies.userId},(err,doc)=>{
  if(doc){
   res.json({
    status:0,
    msg:'',
    result:{
     list:doc.cartList
    }
   })
  }else{
   res.json({
    status:1,
    msg:"购物车列表查询失败"
   })
  }
 })
});

  computed:{
   totalPrice(){
    let total=0;
    this.cartList.forEach((item)=>{
     if(item.checked)
      total+=parseFloat(item.salePrice)*parseInt(item.productNum);
    });
    return total;
   },
   allSelected(){
    let selected=true;
    this.cartList.forEach((item)=>{
     selected=selected&&item.checked;
    });
    console.log(selected);
    return selected;
   }
  },