express+mysql+vue,从零搭建一个商城管理系统12--添加商品到购物车

提示：学习express，搭建管理系统

---

前言

需求：主要学习express，所以先写service部分

一、新建models/cart.js

models/cart.js

const { DataTypes } = require('sequelize');
const sequelize = require('../config/db');

const CartModel = sequelize.define('Cart',{
    id: {
        type: DataTypes.INTEGER,
        autoIncrement: true,
        primaryKey: true
    },
    //用户ID
    userId:DataTypes.STRING,
    //商户ID
    shopId:DataTypes.STRING,
    //商户名
    shopName:DataTypes.STRING,
    //商品ID
    goodsId:DataTypes.STRING,
    //商品名称
    goodsName:DataTypes.STRING,
    //价格
    price:DataTypes.FLOAT,
    //数量
    count:DataTypes.INTEGER,
    //规格
    specs:DataTypes.STRING,
},{
    tableName:'cart'
});

//无cart表创建cart表
CartModel.sync();
module.exports = CartModel;

二、新建dao/cart.js

dao/cart.js

const CartModel = require('../models/cart');
const errFun = (msg,code)=>{
    return {
        code:code||500,
        success:false,
        msg:msg||'操作失败'
    }
}
const sucFun = (data,msg)=>{
    return {
        code:200,
        success:true,
        msg:msg||'操作成功',
        data,
    }
}
const CartDao = {
    //添加商品到购物车
    addGoodsToCart:async(data)=>{
        //如果有当前商品，就追加count  没有的话  新建商品
        const findResult = await CartDao.findGoodsByUserIdAndGoodsIdFromCart(data);
        //如果存再商品
        if(findResult){
            const updateResult = await findResult.update({ count: findResult.count + data.count });
            if(!updateResult)errFun('修改商品数量失败');
            return sucFun(updateResult,'修改商品数量成功');
        }else{
            try{
                const goods = await CartModel.create({
                    userId:data.userId,
                    shopId:data.shopId,
                    shopName:data.shopName,
                    goodsId:data.goodsId,
                    goodsName:data.goodsName,
                    price:data.price,
                    count:data.count,
                    specs:data.specs,
                });
                if(!goods)return errFun('添加商品失败');
                return sucFun(goods,'添加商品成功');
            }catch(err){
                return errFun('添加商品失败');
            }
        }
    },
    //查找商品
    findGoodsByUserIdAndGoodsIdFromCart:async(data)=>{
        try{
            const goods = await CartModel.findOne({where:{userId:data.userId,goodsId:data.goodsId}});
            if(!goods) return null;
            return goods;
        }catch(err){
            return null;
        }
    },
    //通过商品ID查询商品信息
    queryGoodsByUserIdFromCart:async(data)=>{
        //根据goodsId查询goods
        const goodsData = await CartModel.findAll({where:{userId:data.userId}});
        let shopIds = [];
        let resultData = [];
        if(goodsData&&goodsData.length>0){
            goodsData.forEach(item=>{if(shopIds.indexOf(item.shopId)==-1)shopIds.push(item.shopId)});
            goodsData.forEach(item=>{
                let index = shopIds.indexOf(item.shopId);
                let goodsOne = {
                    userId: item.userId,
                    shopId: item.shopId,
                    shopName: item.shopName,
                    goodsId: item.goodsId,
                    goodsName: item.goodsName,
                    count: item.count,
                    price: item.price,
                    specs: item.specs
                }
                if(!resultData[index]){
                    resultData[index] = {
                        shopId:item.shopId,
                        shopName:item.shopName,
                        goods:[ goodsOne ]
                    }
                }else{
                    resultData[index].goods.push(goodsOne);
                }
            });
        }
        if(!resultData||await resultData.length<1)errFun('购物车空空如也');
        return sucFun(resultData,'查询成功');
    },
}

module.exports = CartDao;

三、新建routes/cart.js

routes/cart.js

const CartDao = require('../dao/cart');
const CartRoutes = (router)=>{
    router.post('/cart/addGoodsToCart',async (req,res)=>{
        const result = await CartDao.addGoodsToCart(req.body);
        res.json(result);
    });
    router.get('/cart/queryGoodsByUserIdFromCart',async (req,res)=>{
        const result = await CartDao.queryGoodsByUserIdFromCart(req.query);
        res.json(result);
    });
}
module.exports = CartRoutes;

四、添加商品到购物车

url:http://localhost:1990/goods/addGoodsByShopId
params:{
//下面代码中数据
}

//5次
// "userId": "9e14ebba3be0ae546374e8f5a49f9e80",
// "shopId": "79194be0b10509d407ec414e297da595",
// "shopName": "shop03",
// "goodsId": "59ab7156aab608c14f90ddd7e1dcbdd4",
// "goodsName": "娃哈哈500ml",
// "price": 4.5,
// "count": 1,
// "specs": "500ml/瓶",

//1次
// "userId": "9e14ebba3be0ae546374e8f5a49f9e80",
// "shopId": "a81184a745ad97a4de19823f9782f733",
// "shopName": "shop02",
// "goodsId": "a1787a5e48133e3b688412c27643df80",
// "goodsName": "大辣片",
// "count": 1,
// "price": 4.90,
// "specs": "240克/袋"

//2次
// "userId": "9e14ebba3be0ae546374e8f5a49f9e80",
// "shopId": "a81184a745ad97a4de19823f9782f733",
// "shopName": "shop02",
// "goodsId": "dd427517fbdc6760a14b11ee84772685",
// "goodsName": "卫龙辣条",
// "count": 1,
// "price": 4.90,
// "specs": "35克/袋"

//1次
// "userId": "9e14ebba3be0ae546374e8f5a49f9e80",
// "shopId": "098a0c4828d7d0c78f42e6124f911a77",
// "shopName": "shop01",
// "goodsId": "3984cac360808573a7b703b61a66d0fe",
// "goodsName": "奥利奥原味饼干",
// "count": 1,
// "price": 8.80,
// "specs": "200克/盒"

//2次
// "userId": "9e14ebba3be0ae546374e8f5a49f9e80",
// "shopId": "098a0c4828d7d0c78f42e6124f911a77",
// "shopName": "shop01",
// "goodsId": "94f2965af1c719ade377fd9f85b61e1f",
// "goodsName": "乐事薯片",
// "count": 1,
// "price": 6.40,
// "specs": "160克/罐"

五、查看用户购物车

url:http://localhost:1990/cart/queryGoodsByUserIdFromCart?userId=9e14ebba3be0ae546374e8f5a49f9e80

数据格式：商户—该商户下的商品

{
"code": 200,
"success": true,
"msg": "查询成功",
"data": [
{
"shopId": "79194be0b10509d407ec414e297da595",
"shopName": "shop03",
"goods": [
{
"userId": "9e14ebba3be0ae546374e8f5a49f9e80",
"shopId": "79194be0b10509d407ec414e297da595",
"shopName": "shop03",
"goodsId": "59ab7156aab608c14f90ddd7e1dcbdd4",
"goodsName": "娃哈哈500ml",
"count": 5,
"price": 4.5,
"specs": "500ml/瓶"
}
]
},
{
"shopId": "a81184a745ad97a4de19823f9782f733",
"shopName": "shop02",
"goods": [
{
"userId": "9e14ebba3be0ae546374e8f5a49f9e80",
"shopId": "a81184a745ad97a4de19823f9782f733",
"shopName": "shop02",
"goodsId": "a1787a5e48133e3b688412c27643df80",
"goodsName": "大辣片",
"count": 1,
"price": 4.9,
"specs": "240克/袋"
},
{
"userId": "9e14ebba3be0ae546374e8f5a49f9e80",
"shopId": "a81184a745ad97a4de19823f9782f733",
"shopName": "shop02",
"goodsId": "dd427517fbdc6760a14b11ee84772685",
"goodsName": "卫龙辣条",
"count": 2,
"price": 4.9,
"specs": "35克/袋"
}
]
},
{
"shopId": "098a0c4828d7d0c78f42e6124f911a77",
"shopName": "shop01",
"goods": [
{
"userId": "9e14ebba3be0ae546374e8f5a49f9e80",
"shopId": "098a0c4828d7d0c78f42e6124f911a77",
"shopName": "shop01",
"goodsId": "3984cac360808573a7b703b61a66d0fe",
"goodsName": "奥利奥原味饼干",
"count": 1,
"price": 8.8,
"specs": "200克/盒"
},
{
"userId": "9e14ebba3be0ae546374e8f5a49f9e80",
"shopId": "098a0c4828d7d0c78f42e6124f911a77",
"shopName": "shop01",
"goodsId": "94f2965af1c719ade377fd9f85b61e1f",
"goodsName": "乐事薯片",
"count": 3,
"price": 6.4,
"specs": "160克/罐"
}
]
}
]
}

总结

踩坑路漫漫长@~@

原文地址：https://blog.csdn.net/weixin_44434938/article/details/136707920

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