I've been trying to use the mongoose populate function to connect two models. I can save an object but when trying to retrieve using populate the ObjectIds are just replaced with an empty array.
Many questions seem to have been asked but none have a solution that worked for me
user.js
var mongoose = require('mongoose');
var Schema = mongoose.Schema;
var Route = require('./route')
var passportLocalMongoose = require('passport-local-mongoose');
const postSchema = new Schema ({
text: {
type: String,
default: '',
required: true
}
}, {
timestamps: true
});
const UserSchema = new Schema({
firstname: {
type: String
},
posts: [postSchema],
route: [{
type: mongoose.Schema.Types.ObjectId,
ref: 'Route'
}]
}, {
timestamps: true
});
UserSchema.plugin(passportLocalMongoose);
const User = mongoose.model('User', UserSchema);
module.exports = User;
route.js
var mongoose = require('mongoose');
var Schema = mongoose.Schema;
const locationSchema = new Schema ({
id: {
type: Number,
default: 0,
required: true
},
address: {
type: String,
default: '',
required: true
},
lat: {
type: Number,
default: 0,
required: true
},
lng: {
type: Number,
default: 0,
required: true
}
},{
timestamps: true })
const routeSchema = new Schema ({
locations: [locationSchema],
description: {
journey1: {
type: String,
default: '',
required: false
},
journey2: {
type: String,
default: '',
required: false
},
journey3: {
type: String,
default: '',
required: false
},
journey4: {
type: String,
default: '',
required: false
}
}
}, {
timestamps: true
});
module.exports = mongoose.model('Route', routeSchema);
within REST POST end point
User.findOne({_id: req.user._id}, function(err,user) {
if(user) {
var routed = new Route();
routed.locations = req.body.locations;
routed.description = req.body.description;
user.route.push(routed);
user.save()
.then((user) => {
res.statusCode = 200;
res.setHeader('Content-Type', 'application/json')
res.json(user)
}, (err) => next(err))
} else {
console.log("errored")
err = new Error('User ' + req.body.username + ' not found');
err.status = 404;
return next(err);
}
})
within REST GET end point
User.findOne({_id: req.user._id})
.populate('route')
.then((user) => {
if(user){
console.log("user")
console.log(user)
console.log("routes")
console.log(user.route)
res.statusCode = 200;
res.setHeader('Content-Type', 'application/json')
res.json({success: true, routes: user.route});
}
}, (err) => next(err))
.catch((err) => next(err));
If I remove populate I'll get something like
[
new ObjectId("61f053af7ba46267f4893f8f")
new ObjectId("61f053af7ba46267f4893f8f")
new ObjectId("61f053af7ba46267f4893f8f")
]
from the GET end point but adding it back in returns
[].
My understanding is that in 'new Route()' I'm creating a new Route Object with an Id that gets stored in the User model/document(?). Then when I call populate mongoose searches the Route document for those Ids and converts them to the objects I want. The only issue I could think of is that I'm not creating the Route objects correctly and so no object is being stored with that Id which is why an empty array is returned when I come to try swap Ids with Route objects.
Any ideas or are we all just stumbling in the dark ?
Not entirely sure this is the correct method but instead of instantiating a Route object as displayed I used the Route.create(...) method and then pushed that to the route array and now populate works as expected
The first problem I am having is that whenever I try to delete the Comment, I also try to find the index of that specific comment inside post.comments as well as inside user.comments, it consistently returns -1, the reason why I am trying to find it, is so that I can splice it from the comments array that user and post do have.
The second problem I am having is that whenever I create a comment, I try to store it in the comments array that user and post have, but it stores it only as a string, although I think it is supposed to be stored as an object right?, So I can access it later by populating?
I have been struggling for days now being very frustrated why it does not work. Please help me!
Below will be my two routes, for deleting and creating comments, and my Schemas, Thank You for all the help!
Creating Comments
// #route POST api/posts/comment/:id
// #desc Comment on a post
// #access Private
router.post(
'/comment/:id',
[
auth,
[
check('text', 'Text is required')
.not()
.isEmpty()
]
],
async (req, res) => {
const errors = validationResult(req);
if (!errors.isEmpty()) {
return res.status(400).json({ errors: errors.array() });
}
try {
const post = await Post.findById(req.params.id);
const user = await User.findById(req.user.id)
const newComment = {
text: req.body.text,
post: post._id,
user: req.user.id
};
const comment = new Comment(newComment);
post.comments.unshift(comment._id);
user.comments.unshift(comment._id)
console.log(user.comments);
console.log(post.comments);
console.log(comment)
await post.save();
await comment.save();
await user.save();
res.json(comment);
} catch (err) {
console.error(err.message);
res.status(500).send('Server Error');
}
}
);
Deleting comments
// #route DELETE api/posts/comment/:id/:comment_id
// #desc Delete comment
// #access Private
router.delete('/comment/:id/:comment_id', auth, async (req, res) => {
try {
const post = await Post.findById(req.params.id);
const user = await User.findById(req.user.id);
// Pull out comment by finding it through its id
const comment = await Comment.findById(req.params.comment_id);
// Make sure comment exists
if (!comment) {
return res.status(404).json({ msg: 'Post do not have this comment' });
}
// Check user
if (comment.user.toString() !== req.user.id) {
return res.status(401).json({ msg: 'User not authorized' });
}
// Get The value to be removed
const postCommentIndex = post.comments.findIndex(postComment => postComment === comment._id);
const userCommentIndex = user.comments.findIndex(userComment => userComment === comment._id);
console.log(`This is the post comment index ${postCommentIndex}`);
console.log(`This is the user comment index ${userCommentIndex}`);
post.comments.splice(postCommentIndex, 1);
user.comments.splice(userCommentIndex, 1);
// save user and post
await post.save();
await user.save();
await comment.remove();
// resend the comments that belongs to that post
res.json(post.comments);
} catch (err) {
console.error(err.message);
res.status(500).send('Server Error');
}
});
Schemas:
const mongoose = require('mongoose');
const UserSchema = new mongoose.Schema({
name: {
type: String,
required: true
},
email: {
type: String,
required: true,
unique: true
},
password: {
type: String,
required: true
},
avatar: {
type: String
},
posts: [{type: mongoose.Schema.Types.ObjectId, ref: "Post"}],
comments: [{type: mongoose.Schema.Types.ObjectId, ref: "Comment"}],
date: {
type: Date,
default: Date.now
}
});
module.exports = mongoose.model('User', UserSchema);
const mongoose = require('mongoose');
const Schema = mongoose.Schema;
const PostSchema = new Schema({
user: {
type: Schema.Types.ObjectId,
ref: 'User'
},
text: {
type: String,
required: true
},
likes: [
{
user: {
type: Schema.Types.ObjectId,
ref: 'User'
}
}
],
dislikes: [
{
user: {
type: Schema.Types.ObjectId,
ref: "User"
}
}
],
comments: [{type: Schema.Types.ObjectId, ref: "Comment"}],
date: {
type: Date,
default: Date.now
}
});
module.exports = mongoose.model('Post', PostSchema);
const mongoose = require("mongoose")
const Schema = mongoose.Schema;
const CommentSchema = new Schema({
user: {
type: Schema.Types.ObjectId,
ref: 'User'
},
post: {
type: Schema.Types.ObjectId,
ref: "Post"
},
text: {
type: String,
required: true
},
date: {
type: Date,
default: Date.now
}
})
module.exports = mongoose.model("Comment", CommentSchema);
I think you need to redesign your schemas in a simpler way, there are too many references between the models, and this causes issues, for example you have 5 db access when you want to create a comment, and 6 db access when you want to delete a comment.
I would create the user schema like this removing the posts and comment references, but later when we want to access the posts from users, I set up virtual populate.
const UserSchema = new Schema(
{
name: {
type: String,
required: true
},
email: {
type: String,
required: true,
unique: true
},
password: {
type: String,
required: true
},
avatar: {
type: String
},
date: {
type: Date,
default: Date.now
}
},
{
toJSON: { virtuals: true }
}
);
UserSchema.virtual("posts", {
ref: "Post",
localField: "_id",
foreignField: "user"
});
And in the posts schema, I removed the comments references.
(For simplicity I removed likes and dislikes fields.)
const PostSchema = new Schema(
{
user: {
type: Schema.Types.ObjectId,
ref: "User"
},
text: {
type: String,
required: true
},
date: {
type: Date,
default: Date.now
}
},
{
toJSON: { virtuals: true }
}
);
PostSchema.virtual("comments", {
ref: "Comment",
localField: "_id",
foreignField: "post"
});
Comment schema can stay as it is.
Now to add a comment to a post, we only need 2 db access, one for checking if post exists, and one for creating the post.
router.post(
"/comment/:id",
[
auth,
[
check("text", "Text is required")
.not()
.isEmpty()
]
],
async (req, res) => {
const errors = validationResult(req);
if (!errors.isEmpty()) {
return res.status(400).json({ errors: errors.array() });
}
try {
const post = await Post.findById(req.params.id);
if (!post) {
return res.status(404).json({ msg: "Post not found" });
}
let comment = new Comment({
text: req.body.text,
post: req.params.id,
user: req.user.id
});
comment = await comment.save();
res.json(comment);
} catch (err) {
console.error(err.message);
res.status(500).send("Server Error");
}
}
);
Let's say we have these 2 users:
{
"_id" : ObjectId("5e216d74e7138b638cac040d"),
"name" : "user1"
}
{
"_id" : ObjectId("5e217192d204a26834d013e8"),
"name" : "user2"
}
User1 with _id:"5e216d74e7138b638cac040d" has this post.
{
"_id": "5e2170e7d204a26834d013e6",
"user": "5e216d74e7138b638cac040d",
"text": "Post 1",
"date": "2020-01-17T08:31:35.699Z",
"__v": 0,
"id": "5e2170e7d204a26834d013e6"
}
Let's say user2 with _id:"5e217192d204a26834d013e8" commented on this post two times like this:
{
"_id" : ObjectId("5e2172a4957c02689c9840d6"),
"text" : "User2 commented on user1 post1",
"post" : ObjectId("5e2170e7d204a26834d013e6"),
"user" : ObjectId("5e217192d204a26834d013e8"),
"date" : ISODate("2020-01-17T11:39:00.396+03:00"),
"__v" : 0
},
{
"_id": "5e21730d468bbb7ce8060ace",
"text": "User2 commented again on user1 post1",
"post": "5e2170e7d204a26834d013e6",
"user": "5e217192d204a26834d013e8",
"date": "2020-01-17T08:40:45.997Z",
"__v": 0
}
To remove a comment we can use the following route, as you see we decreased the db access from 6 to 3, and code is shorter and cleaner.
router.delete("/comment/:id/:comment_id", auth, async (req, res) => {
try {
const comment = await Comment.findById(req.params.comment_id);
if (!comment) {
return res.status(404).json({ msg: "Post do not have this comment" });
}
if (comment.user.toString() !== req.user.id) {
return res.status(401).json({ msg: "User not authorized" });
}
await comment.remove();
// resend the comments that belongs to that post
const postComments = await Comment.find({ post: req.params.id });
res.json(postComments);
} catch (err) {
console.error(err.message);
res.status(500).send("Server Error");
}
});
Now you may ask, how will access the posts from an user? Since we setup virtual populate in our user schema, we can populate the posts like this:
router.get("/users/:id/posts", async (req, res) => {
const result = await User.findById(req.params.id).populate("posts");
res.send(result);
});
You can try this code snipet :
Comment.deleteOne({
_id: comment.id
}, function (err) {
if (err) {
console.log(err);
return res.send(err.message);
}
res.send('success');
});
I am making a node API. I am stuck at adding a comment to a story.
I am able to create a comment but instead of pushing it to a given story, it was trying to create a new instance of story.
Story.findOne(req.params.id, (err, foundstory) => {
if(err){
res.status(500).json({msg:err})
}else{
let comment = new Comment()
comment.body = req.body.body
comment.author = req.body.author
console.log(foundstory)
//save comment//
comment.save((err, comment) => {
if(err){
res.status(500).json({msg:err})
}else{
//pushing comment to comments array (ref) in story
foundstory.comments.push(comment)
foundstory.save()
res.status(200).json({msg:"Comment saved"})
}
})
}
})
Story Schema
import mongoose from 'mongoose'
import User from './user'
import Comment from './comment'
const Schema = mongoose.Schema
const ObjectID = mongoose.Schema.Types.ObjectId
const storySchema = new Schema({
//subdoc ref from user
author: {type: ObjectID, ref: 'User'},
//subdoc ref from comment
comments: [{
type: ObjectID,
ref: 'Comment'
}],
//contents of story//
title: {type: String, required: true},
body: {type: String, required: true},
date: {type: Date, default: Date.now()},
tags: [{type: String}]
})
module.exports = mongoose.model('Story', storySchema)
Comment Schema
import mongoose from 'mongoose'
import User from './user'
const Schema = mongoose.Schema
const ObjectID = mongoose.Schema.Types.ObjectId
const commentSchema = new Schema({
body : {type: String, required: true},
author: {type: ObjectID, ref: 'User'}
})
module.exports = mongoose.model('Comment', commentSchema)
I have an array of type "Comment" in my "Story" schema. My attempt is to push those comment to that array.
try changing your code like this:
Story.findById(req.params.id, (err, foundstory) => {
if (err) res.status(500).json({
msg: err
});
else if (!foundStory) res.status(400).json({
msg: "Story Not Found"
});
else {
let comment = new Comment();
comment.body = req.body.body;
comment.author = req.body.author;
//save comment//
comment.save(async (err, comment) => {
if (err) res.status(500).json({
msg: err
});
else {
foundstory.comments.push(comment._id);
await foundstory.save();
res.status(200).json({
msg: "Comment saved"
})
}
})
}
})
I've changed the findOne() method with findById(), also the 'foundstory.save()' method is an asynchronous call, so i used async\await to handle it.
Hope this helps :)
const UniversitySchema = new Schema({
university_name: {
type:String,
},
status: {
type: String
}
});
const CollageSchema = new Schema({
collage_name: {
type:String,
required: [true,'Name field is required']
},
university_id: {
type: [{ type: Schema.Types.ObjectId ,
ref: 'university' }]
},
type: {
type:String
}
});
router.delete('/university/:id',function(req,res,next){
University.findByIdAndRemove({_id:req.params.id}).then(function(detail){
res.send(detail);
});
});
I have referenced _id of UniversitySchema in CollageSchema and if I delete any university corresponding collage should be deleted. How to do this?
With an additional mongo call on collages collection, using Promise.all() :
router.delete('/university/:id',function(req,res,next){
const ObjectId = require('mongodb').ObjectId;
const _id = ObjectId(req.params.id);
const removeUniversity = University.findByIdAndRemove({ _id: _id });
const removeCollage = Collage.remove({ university_id: _id });
Promise
.all([removeUniversity, removeCollage])
.then(function(values) {
const detail = values[0];
res.send(detail);
})
.catch((err) => console.error(err));
});
i'm trying to find all blogs that a user has created with his userId.
I have the following mongoose model for the blog
var mongoose = require('mongoose');
var BlogSchema = new mongoose.Schema({
title:{
type: String,
required: true,
},
content:{
type: String,
required: true
},
_creator:{
type: mongoose.Schema.Types.ObjectId,
required: true
}
})
BlogSchema.statics.findBlogs = function(id){
var Blog = this;
return Blog.find(id).then((blog)=>{
console.log(blog)
}).catch((e)=>{
console.log('failed')
})
}
var Blog = mongoose.model('Blogs', BlogSchema)
module.exports = {Blog};
then in my server.js i have this
app.get('/get/blogs', authenticate, (req, res)=>{
var userId = req.user._id
console.log(userId)
Blog.findBlogs(userId).then((data)=>{
res.send(data)
}).catch((e)=>{
res.sendStatus(404)
})
})
but it returns an empty array, how should i approach this?
The line
return Blog.find(id).then((blog) => {
should probably say
return Blog.find({ _creator: id }).then((blogs) => {
Try this
blog.find({creatorid:user.id},function(err,data){
//data will be here
})