Node JS/Express 路由

Question

我需要一些关于在我的 Node/Express 应用中进行路由的指导。最初，我从业务模型创建了一个新业务（工作正常）。创建业务后，我想要一条单独的路线来添加该业务提供的当前外汇汇率（这些字段将每天更新）。我的商业模式看起来像这样（为了示例而简化）：

let businessSchema = new mongoose.Schema({
   name: String,
   category: String,
   longDescription: String,
   images: [ {url: String, public_id: String} ],

   usdHkd: { type: String, default: "" },
   hkdUsd: { type: String, default: "" },
   rateCreatedAt: {
      type:Date,
      default:Date.now
   },
});

首次创建业务时，仅填充名称、类别、longDesc 和图像，并使用外汇汇率字段的默认值。使用这些路线效果很好：

/* GET business new /business/new */
router.get("/new", isLoggedIn, asyncErrorHandler(businessNew));

/* POST business create /business */
router.post('/', isLoggedIn, upload.fields([{ name: 'images', maxCount: 10 }]), asyncErrorHandler(businessCreate));

然后我像这样设置单独的路线/控制器，以便随后添加外汇汇率，但我认为这些定义不正确：

/* GET business index /business */
router.get('/:id/remittance/new', asyncErrorHandler(remittanceNew));

/* GET business index /business */
router.put('/:id/remittance', asyncErrorHandler(remittanceCreate));

    //Remittances New
    async remittanceNew (req, res, next) {
        let business = await Business.findById(req.params.id);
        res.render('remittanceViews/newRemittance', { business }); 
    },

    //Business Update
    async remittanceCreate (req, res, next) {

        let business = await Business.findByIdAndUpdate(req.params.id, req.body.business);
        console.log(business);

        //update the post with any new properties
        business.usdHkd = req.body.business.usdHkd;
        business.hkdUsd = req.body.business.hkdUsd;
        business.rateCreatedAt = req.body.business.rateCreatedAt;

        //save the updated post in the db
        business.save();
        //redirect to show page
        res.redirect(`/business/${business.id}`);
    },

我尝试更新时收到的错误消息是：

Cannot read property 'usdHkd' of undefined

谁能告诉我这里哪里出错了？谢谢

Answer 1

错误信息表明usdHkd 的父变量在未定义。很可能，此错误来自business.usdHkd = req.body.business.usdHkd; 中的business.usdHkd（您可以通过在此行周围添加更多console.log() 行并检查输出来确认）。

如果business.usdHkd = req.body.business.usdHkd; 给出错误，这意味着business 是未定义。但是，您不需要此行，因为 business 已由 findByIdAndUpdate 更新。

阅读：Model.findByIdAndUpdate() 和 Promises in Mongoose

//Business Update
async remittanceCreate (req, res, next) {

    let business = await Business.findByIdAndUpdate(req.params.id, req.body.business);
    console.log(business);

    // Below code is not required since findByIdAndUpdate() will update your model
    /*
    //update the post with any new properties
    business.usdHkd = req.body.business.usdHkd;
    business.hkdUsd = req.body.business.hkdUsd;
    business.rateCreatedAt = req.body.business.rateCreatedAt;

    //save the updated post in the db
    business.save();
    */

    //redirect to show page
    res.redirect(`/business/${business.id}`);
},

更新

您告诉过business 已定义，但尚未更新。原因是 findOneAndUpdate() 需要将 new 选项设置为 true 否则 findOneAndUpdate() 返回旧对象（在更新之前 - 在某种意义上）。所以，请将remittanceCreate()的第一行改为：

let business = await Business.findByIdAndUpdate(req.params.id, req.body.business, {new: true});