Question

我是Node，Mongoose和与Backend相关的一切的新手。我最近遇到了一个问题。我无法弄清楚，因为开发课程的练习文件中的相同代码似乎是相同的。不过问题仍然没有解决。我想与教程一起编码，就是要为Mongoose数据库中显示的每个露营地部分定义一个Mongoose模型，以供注释。我有models文件夹，可以在其中定义露营地和注释的模型，还有一个seeds.js文件，可以在其中将数据动态添加到露营地（以便使其随即显示注释），然后添加注释。这些文件的实际代码如下所示： app.js->

# A tibble: 5 x 3
# Groups:   MMR_NBR [4]
  Timestamp           MMR_NBR Action  
  <dttm>              <fct>   <fct>   
1 2018-08-14 11:22:18 W00364  SAP Load
2 2018-08-14 11:30:03 K00364  SAP Load
3 2018-08-14 11:32:26 K00364  SAP Load
4 2018-08-22 16:34:53 K00646  SAP Load
5 2018-08-23 11:47:15 B00218  SAP Load

seeds.js ---->

var express = require("express");
var app = express();
var bodyParser = require("body-parser");
var mongoose = require('mongoose');
var Campground=require("./models/campground");
var seedDB = require("./seeds");
var PORT = process.env.IP || 3200;

seedDB();

mongoose.connect('mongodb://localhost/yelp_camp', { useNewUrlParser: true }, 
(err, res) => {
if (err) throw err;
console.log('Database online');
});
app.use(bodyParser.urlencoded({ extended: true }));
app.set("view engine", "ejs");

//schema

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

});

app.get("/campgrounds/tornike", function (req, res) {
//get all campgrounds
res.send(Campground.name);

});

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

});

app.post("/campgrounds", function (req, res) {
var name = req.body.name;
var image = req.body.image;
var desc = req.body.description;
var newCampground = { name: name, image: image, description:desc };
//create new camp and save to database
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");

});

//shows more info about camp
app.get("/campgrounds/:id", function (req, res) {
//find camp with provided id 
Campground.findById(req.params.id, function (err, foundCampground) {
    if (err) {
        console.log(err);
    } else {
        //render show template
        res.render("show", { campground: foundCampground });
    }
});

});


app.listen(PORT, process.env.IP, function () {
console.log("camp");
});

comment.js --->

var mongoose = require("mongoose");
var Campground = require("./models/campground");
var Comment = require("./models/comment");

var data = [
{
name: "something",
image: "image URL",
description: "blah blah bla1"
},

{
name: "something",
image: "image URL",
description: "blah blah bla2"
},

{
name: "something",
image: "image URL",
description: "blah blah bla3"
}
];

function seedDB() {
Campground.deleteMany({}, function(err) {
console.log("removed camps");
data.forEach(function(seed) {
  Campground.create(seed, function(err, data) {
    if (err) {
      console.log(err);
    } else {
      console.log("added campground");
      Comment.create(
        {
          text: "dubdabdubadah",
          author: "Homer"
        },
        function(err, comment) {
          if (err) {
            console.log(err);
          } else {
            campground.comments.push(comment);
            campground.save();
            console.log("Created new comment");
          }
        }
      );
    }
  });
});
});
}

module.exports = seedDB;

campground.js ---->

var mongoose = require("mongoose");


var commentSchema= new mongoose.Schema({
text:String,
author:String
});


module.exports=mongoose.model("Comment", commentSchema);

此行上的seed.js文件中发生错误campground.comments.push（comment）; 看起来像这样：

var mongoose = require("mongoose");

var campgroundSchema = new mongoose.Schema({
name: String,
image: String,
description: String,
comments: [
{
  type: mongoose.Schema.Types.ObjectId,
  ref: "Comment"
}
]
});

module.exports = mongoose.model("Campground", campgroundSchema);

与将代码与练习文件的代码进行比较时相比，我实际上无法绕开它-一样。我唯一能想到的是猫鼬express的版本，或者其他可能不相关或不赞成使用某些方法的方法，但老实说，不知道出了什么问题。我已经尝试解决了好几天。有什么想法的人吗？

Answer 1

错误消息告诉您，您尚未定义名为campground的变量，而您没有定义它是正确的。

要解决此问题，请在data回调中将campground更改为Campground.create：

Campground.create(seed, function(err, campground) {

Node中的猫鼬模式引用存在问题

1 个答案: