Question

我的nodejs服务器连接到mongoDB时遇到问题

这是app.js的主要代码

var express = require("express")
var app = express();
var bodyParser = require("body-parser");
var mongoose = require("mongoose")

mongoose.connect("mongodb://localhost:27017/yelpcamp", {useNewUrlParser: true, useUnifiedTopology: true});
app.use(bodyParser.urlencoded({extended: true}));
app.set("view engine", "ejs");

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

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



app.get("/", function(req,res){
    res.render("landing")
})

app.get("/campgrounds", function(req,res){
    Campground.find({}, function(err, allcampgrounds){
        if(err){
            console.log()
        } else {
            res.render("index", {campgrounds:allcampgrounds});
        }
    })
    
})

app.post("/campgrounds", function(req,res){
    var name = req.body.name;
    var image = req.body.image;
    var newCampground = {name : name, image: image}
    Campground.create(newCampground, function(err, newlyCreated){
        if(err){
            console.log(err)
        } else {
            res.redirect("/campgrounds")
        }
    })
    
})

app.get("/campgrounds/new", function(req,res){
    res.render("new.ejs")
})

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

app.listen(3000, function(){
    console.log("The Server has started listening on Port 3000!")
})

那是我的主要路线，我遇到的问题是我试图拨打的显示页面上的/ campgrounds /：id使用最后一条路线

，它只返回此错误：

TypeError： /mnt/c/Users/zhelf/Downloads/test/yelpcamp/views/show.ejs:4 2 | 3 |

4 |

<％= campground.name％>

无法读取null的属性“名称” 在评估（/mnt/c/Users/zhelf/Downloads/test/yelpcamp/views/show.ejs:10:37）在展会上（/mnt/c/Users/zhelf/Downloads/test/yelpcamp/node_modules/ejs/lib/ejs.js:691:17）在tryHandleCache（/mnt/c/Users/zhelf/Downloads/test/yelpcamp/node_modules/ejs/lib/ejs.js:272:36）在View.exports.renderFile [作为引擎]（/mnt/c/Users/zhelf/Downloads/test/yelpcamp/node_modules/ejs/lib/ejs.js:489:10）在View.render（/mnt/c/Users/zhelf/Downloads/test/yelpcamp/node_modules/express/lib/view.js:135:8）在tryRender（/mnt/c/Users/zhelf/Downloads/test/yelpcamp/node_modules/express/lib/application.js:640:10）在Function.render（/mnt/c/Users/zhelf/Downloads/test/yelpcamp/node_modules/express/lib/application.js:592:3）在ServerResponse.render（/mnt/c/Users/zhelf/Downloads/test/yelpcamp/node_modules/express/lib/response.js:1012:7）在/mnt/c/Users/zhelf/Downloads/test/yelpcamp/app.js:85:17 在/mnt/c/Users/zhelf/Downloads/test/yelpcamp/node_modules/mongoose/lib/model.js:4824:16 在/mnt/c/Users/zhelf/Downloads/test/yelpcamp/node_modules/mongoose/lib/model.js:4824:16 在/mnt/c/Users/zhelf/Downloads/test/yelpcamp/node_modules/mongoose/lib/helpers/promiseOrCallback.js:24:16 在/mnt/c/Users/zhelf/Downloads/test/yelpcamp/node_modules/mongoose/lib/model.js:4847:21 在/mnt/c/Users/zhelf/Downloads/test/yelpcamp/node_modules/mongoose/lib/query.js:4390:11 在/mnt/c/Users/zhelf/Downloads/test/yelpcamp/node_modules/kareem/index.js:135:16 在processTicksAndRejections（internal / process / task_queues.js：79：11）

Answer 1

更改 Campground.findById(req.params._id, function(err, foundCampground)

到 Campground.findById(req.params.id, function(err, foundCampground)

因为您需要提供来自“ / campgrounds /：id”路线的ID

类型错误：无法读取null的属性“名称”

1 个答案: