I'm trying mongoose populate query options but i don't know why the query options doesn't work.
I have user schema:
const mongoose = require('mongoose');
const Schema = mongoose.Schema;
const UserSchema = new Schema(
{
username: { type: String, required: true },
email: { type: String },
name: { type: String },
address: { type: String }
},
{ timestamps: true }
);
module.exports = mongoose.model('User', UserSchema);
and feed schema:
const mongoose = require('mongoose');
const Schema = mongoose.Schema;
const FeedSchema = new Schema(
{
user: { type: Schema.ObjectId, ref: 'User' },
notes: { type: String, required: true },
trx_date: { type: Date },
status: { type: Boolean, Default: true }
},
{ timestamps: true }
);
FeedSchema.set('toObject', { getters: true });
module.exports = mongoose.model('Feed', FeedSchema);
I want to find all feed by user id, i used async waterfall like the following code:
async.waterfall([
function(callback) {
User
.findOne({ 'username': username })
.exec((err, result) => {
if (result) {
callback(null, result);
} else {
callback(err);
}
});
},
function(userid, callback) {
// find user's feed
Feed
.find({})
// .populate('user', {_id: userid._id}) <== this one also doesn't work
.populate({
path: 'user',
match: { '_id': { $in: userid._id } }
})
.exec(callback);
}
], function(err, docs) {
if (err) {
return next(err);
}
console.log(docs);
});
With above code, i got all feeds, and it seems like the query option do not work at all, did i doing it wrong ?
Any help would be appreciate.
Not sure why you are looking to match "after" population when the value of _id is what is already stored in the "user" property "before" you even populate.
As such it's really just a simple "query" condition to .find() instead:
async.waterfall([
(callback) =>
User.findOne({ 'username': username }).exec(callback),
(user, callback) => {
if (!user) callback(new Error('not found')); // throw here if not found
// find user's feed
Feed
.find({ user: user._id })
.populate('user')
.exec(callback);
}
], function(err, docs) {
if (err) {
return next(err);
}
console.log(docs);
});
Keeping in mind of course that the .findOne() is returning the whole document, so you just want the _id property in the new query. Also note that the "juggling" in the initial waterfall function is not necessary. If there is an error then it will "fast fail" to the end callback, or otherwise pass through the result where it is not. Delate "not found" to the next method instead.
Of course this really is not necessary since "Promises" have been around for some time and you really should be using them:
User.findOne({ "username": username })
.then( user => Feed.find({ "user": user._id }).populate('user') )
.then( feeds => /* do something */ )
.catch(err => /* do something with any error */)
Or indeed using $lookup where you MongoDB supports it:
User.aggregate([
{ "$match": { "username": username } },
{ "$lookup": {
"from": Feed.collection.name,
"localField": "_id",
"foreignField": "user",
"as": "feeds"
}}
]).then( user => /* User with feeds in array /* )
Which is a bit different in output, and you could actually change it to look the same with a bit of manipulation, but this should give you the general idea.
Importantly is generally better to let the server do the join rather than issue multiple requests, which increases latency at the very least.
Related
I am having a bit of an issue with Mongoose/MongoDB this afternoon. I have a situation where I need to return all items from a collection, and doing so means that I do not pass in any search params to mongoose.find().
This is the controller that handles the get all request:
exports.get_all_posts = async (req, res, next) => {
const { params } = req;
const { sortby } = params;
//Sortby param takes two arguments for now: most_recent, oldest
try {
const getAllPosts = await BlogPost.find({}, { _id: 0 });
console.log(getAllPosts);
if (!getAllPosts) throw new Error('Could not get blog posts.');
res.json({
posts: date_.sort(getAllPosts, sortby)
});
} catch (error) {
next(error);
}
};
This is particularly where I think the issue is coming from:
const getAllPosts = await BlogPost.find({}, { _id: 0 });
I am passing an empty search parameter and then removing the _id so that it doesn't throw an error telling me that I need to provide the _id.
However I still need to be able to pull in all of the posts. My items from this collection return as normal, just without their _id's.
Here is my model for the blog posts:
const mongoose = require('mongoose');
const BlogPostSchema = new mongoose.Schema({
date: {
type: Date,
required: true
},
title: {
type: String,
required: true
},
author: {
type: String,
required: true
},
likes: {
type: Number,
required: false
},
post_body: {
type: String,
required: true
},
description: {
type: String,
required: true
},
tags: [
{
type: String,
required: false
}
],
featuredImage: {
type: String,
required: false
},
draft: {
type: Boolean,
required: true
}
});
module.exports = mongoose.model('BlogPost', BlogPostSchema);
One thing to note is that I have not defined an _id. Mongoose automatically adds in the _id field before saving a schema, so I think it is okay without it, as it has been in the past.
Thanks in advance for reading and any input!
Just as Joe has commented, { _id: 0 } as the second parameter is making your query not return the _id field.
Also as he said, there should be no problem whatsoever with using find({}).
Since other than what has already been stated, I couldn't figure out any mistake in the code snippets you provided, I guess this error could be coming from somewhere else in your project.
exports.get_all_posts = async (req, res, next) => { const { params } = req; const { sortby } = params;
try { const getAllPosts = await BlogPost.find({}); console.log(getAllPosts); if (!getAllPosts) throw new Error('Could not get blog posts.'); res.json({ posts: date_.sort(getAllPosts, sortby) }); } catch (error) { next(error); } };
no need to {_id:0} in the find() method because this method retrieve all the documents in the db collection
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');
});
Baiscally making a node.js, mongodb add friends functionality where having the option of list user to add in friends list, sent friends request, accept friends request, delete friends request, block friends request.
Register Collection
const mongoose = require('mongoose');
const Schema = mongoose.Schema;
let Register = new Schema(
First_Name:{
type: String,
required: true
},
Last_Name: {
type: String
},
Email: {
type: String,
unique: true,
lowercase: true,
required: true
},
Friends:[{type: String}],
});
module.exports = mongoose.model('Register', Register);
Friends Collection
const mongoose = require('mongoose');
const Schema = mongoose.Schema;
var ObjectId = require('mongodb').ObjectID;
let Friends = new Schema({
Requester: {
type: ObjectId,
required: true
},
Recipients: [{Recipient:{type:ObjectId},Status:{type:Number}}],
});
module.exports = mongoose.model('Friends', Friends);
Inside Node.js Post API
var Register = require('../models/register.model');
var Friends =require('../models/friends.model');
router.post('/getdata',function(req,res)
{
let Email="example#example.com";
Register.findOne({ Email : Emails }, function(err, user) {
Friends.findOne({ Requester :user._id }, function(err, user1) {
Register.find({$and:[{Friends:{$nin:[user._id]}},{_id:{$ne:user1.Recipients.Recipient}}]},function(err, user2) {
console.log("user2",user2);
//Here User2 data is not coming
//How to get data so can able to list user that is not added yet in FriendList
//Mainly user1.Recipients.Recipient this is not working because //Recipients is array so how can match all data with array, if i am //using loop then find return data scope ends on inside find closing //braces only.
//Any suggestion
});
});
});
So if I have it correct, you want to do the following:
Find a registration based on a given email
Find the friends related to this user
Find registrations that are not yet in the friend list of the user
Also, given what you've typed, I'm assuming A can be the friend of B, but that doesn't mean B is the friend of A.
While the data structure you currently have may not be optimal for this, I'll show you the proper queries for this:
var Register = require('../models/register.model');
var Friends =require('../models/friends.model');
router.post('/getdata',function(req,res) {
const email = "example#example.com";
Register.findOne({ Email: email }, function(err, user) {
if (err) {
console.error(err);
return;
}
Friends.findOne({ Requester: user._id }, function(err, friend) {
if (err) {
console.error(err);
return;
}
const reciptientIds = friend.Recipients.map(function (recipient) {
return recipient.Recipient.toString();
});
Register.find({Friends: { $ne: user._id }, {_id: { $nin: recipientIds }}, function(err, notFriendedUsers) {
if (err) {
console.error(err);
return;
}
console.log(notFriendedUsers);
});
});
});
});
P.S. This "callback hell" can be easily reduced using promises or await/defer
Finally able to solve it, below is the solution
var Register = require('../models/register.model');
var Friends =require('../models/friends.model');
router.post('/getdata',function(req,res)
{
let Emails="example#example.com";
Register.findOne({$and:[{ Email : Emails}] }, function(err, user) {
if (err) {
console.error(err);
return;
}
Friends
.findOne({ Requester: user._id },
{ _id: 0} )
.sort({ Recipients: 1 })
.select( 'Recipients' )
.exec(function(err, docs){
docs = docs.Recipients.map(function(doc) {
return doc.Recipient; });
if(err){
res.json(err)
} else {
console.log(docs,"docs");
Register.find({$and:[{Friends: { $ne: user._id }},{_id: { $nin: docs }},{_id:{$ne:user._id}}]}, function(err, notFriendedUsers) {
if (err) {
console.error(err);
return;
}
console.log(notFriendedUsers);
});
}
})
});
I have a User model that contains an array of customers. I want to delete a specific customer based on the customer _id. From what I've read in the Mongoose docs, I should use Model.deleteOne to delete a single document.
Here is my attempt
User Schema (it's been shortened for brevity):
const mongoose = require('mongoose');
const UserSchema = new mongoose.Schema({
username: {
type: String,
default: ''
},
password: {
type: String,
default: '',
},
registerDate: {
type: Date,
default: Date.now()
},
customer: [{
name: {
type: String,
default: '',
},
email: {
type: String,
default: 'No email name found'
},
fleet: [{
unitNumber: {
type: String,
default: 'N/A',
}
}]
}]
});
module.exports = mongoose.model('User', UserSchema);
Here is a look at the route and controller:
const express = require('express');
const router = express.Router();
const customer_controller = require('../../controllers/customers');
router.delete('/customers/:custid', customer_controller.customer_remove);
module.exports = router;
And finally the controller:
exports.customer_remove = (req, res) => {
const { params } = req;
const { custid } = params;
User.deleteOne({ 'customer._id': custid }, (err) => {
if (err)
throw err;
else
console.log(custid, 'is deleted');
});
};
From what I thought, User.deleteOne({ 'customer.id': custid }) would find the customer _id matching the custid that is passed in via the req.params. When I test this route in Postman, it deletes the entire User collection that the customer is found in, instead of just deleting the customer. Can I get a nudge in the right direction? I feel like I am close here (or not lol).
deleteOne operates at the document level, so your code will delete the first User document that contains a customer element with a matching _id.
Instead, you want update the user document(s) to remove a specific element from the customer array field using $pull. To remove the customer from all users:
User.updateMany({}, { $pull: { customer: { _id: custid } } }, (err) => { ...
Using Mongoose you can do this:
model.findOneAndUpdate({ 'customer._id': custid }, {$pull: { $pull: {
customer: { _id: custid } }}, {new: true}).lean();
Removing subdocs.
Each sub document has an _id by default. Mongoose document arrays have a special id method for searching a document array to find a document with a given _id.
Visit: https://mongoosejs.com/docs/subdocs.html
parent.children.id(_id).remove();
Use async-await, may be that will work.
exports.customer_remove = async (req, res) => {
const { params } = req;
const { custid } = params;
try {
await User.deleteOne({ 'customer._id': custid });
console.log(custid, 'is deleted');
} catch (err) {
throw err;
}
};
I'm trying to do some relations between my schemas and I have some problems with my solution.
user schema:
let userSchema = new mongoose.Schema({
username: { type:String, default:null },
gender: { type:String, default:null },
role: { type: mongoose.Schema.Types.ObjectId, ref: 'Role', required: true },
});
role schema:
let roleSchema = new mongoose.Schema({
name: { type:String, default:"Player" },
privileges:
[
{
resource: String ,
actions: [ String ]
},
],
});
and my query is
User.find({ "email":email }).populate({path: 'role', model: 'Role'}).limit(1).exec().
then(results => {
if (results.length) {
user = results[0];
console.log(user.role.privileges);
}
else {
throw new APIError("login_failed");
}
})
I need to access to the first element of privileges and Thank you.
The first parameter returned by Mongoose (and Node in general) is not your data. It's the error (if any). You need to write then( (error, results) => {
I need to access to the first element of privileges
privileges being an array, simply access the first element using :
user.role.privileges[0]
As an aside, you can also use Mongoose's .findOne() method, instead of .find().limit(1) :
User
.findOne({ email }) // Shorthand for { email : email }
.populate({path: 'role', model: 'Role'})
.exec()
.then( (error, user) => {
if(error || !user) throw new APIError("login_failed");
console.log(user.role.privileges[0]);
})