無法讀取 null 節點的屬性“名稱”

Question

圖式

var campgroundSchema = new mongoose.Schema({
     name: String,
     image: String,
     description: String,
     _id: String
});

var Campground = mongoose.model("Campground", campgroundSchema);

app.get("/campgrounds/:id",function(req , res){
    Campground.findById(req.params._id, function(err, foundCampgrounds){
        if(err){
            console.log(err);
        }else{
            res.render("show", {campground: foundCampgrounds});
        }
    });
});

顯示.ejs

<%- include('partials/header')  %> 
<h1>this is a show template</h1>
<p><%= campground.name %></p>
<img src="<%=campground.image%>">

<%- include('partials/footer')  %> 

錯誤

TypeError: /home/ec2-user/environment/Yelpcamp/v2/views/show.ejs:3`
    1| <%- include('partials/header')  %> `
    2| <h1>this is a show template</h1>`
 >> 3| <p><%= campground.name %></p>`
    4| <img src="<%=campground.image%>">`
    5| 
    6| <%- include('partials/footer')  %>` 

無法在 show (/home/ec2-user/environment/Yelpcamp/v2/) 上讀取 null 的屬性“名稱” node_modules/ejs/lib/ejs.js:656:17) 在 tryHandleCache (/home/ec2-user/environment/Yelpcamp/v2/node_modules/ejs/lib/ejs.js:254:36) 在 View.exports.renderFile [作為引擎] (/home/ec2-user/environment/Yelpcamp/v2/node_modules/ejs/lib/ejs.js:459:10) 在 View.render (/home/ec2-user/environment/Yelpcamp/v2/ node_modules/express/lib/view.js:135:8) 在 tryRender (/home/ec2-user/environment/Yelpcamp/v2/node_modules/express/lib/application.js:640:10) 在 Function.render (/ home/ec2-user/environment/Yelpcamp/v2/node_modules/express/lib/application.js:592:3) 在 ServerResponse.render (/home/ec2-user/environment/Yelpcamp/v2/node_modules/express/lib/ response.js:1012:7) 在/home/ec2-user/environment/Yelpcamp/v2/app.js:74:17 在/home/ec2-user/environment/Yelpcamp/v2/node_modules/mongoose/lib/model .js:4828:16 在 /home/ec2-user/environment/Yelpc amp/v2/node_modules/mongoose/lib/query.js:4390:12 在 model.Query.Query._completeOne (/home/ec2-user/environment/Yelpcamp/v2/node_modules/mongoose/lib/query.js:2074 :12) 在 Immediate.Query.base.findOne.call (/home/ec2-user/environment/Yelpcamp/v2/node_modules/mongoose/lib/query.js:2136:10) 在 Immediate。 (/home/ec2-user/environment/Yelpcamp/v2/node_modules/mquery/lib/utils.js:116:16) 在 runCallback (timers.js:705:18) 在 tryOnImmediate (timers.js:676:5)

即使在重新啟動 mongodb 后我仍收到此錯誤，我如何檢查名稱是否為 null

Answer 1

布魯它必須是沒有下划線的 req.params.id:)

Answer 2

解決辦法是：

1. 重啟服務器后，打開“/campgrounds”頁面，在我的例子中是“http://localhost:3000/campgrounds”
2. 然后點擊更多信息。

我也遇到了同樣的問題，但是當我從 /campgrounds 頁面打開時它就解決了

Answer 3

問題的解決有點簡單，就在這行代碼中

res.redirect("/campgrounds"{campground:newCampgrounds})

您可能缺少將newCampgrounds引用到將在 show.ejs 中用作 campground.name 或 campground.image 等的campground.name campground.image 。