Is it possible to query subdocuments directly using mongoose? - node.js

Question

let's say there was a User model and a Post model. In this situation User's would have many posts; User would be the parent and Post would be the child. Is it possible to query for posts directly?
For instance if I wanted to do something like
app.get('/post/search/:query', (req,res) => {
Posts.find({title: req.params.query }, (err,post) => {
res.send(JSON.stringify(post))
})
})
or would one have to do:
app.get('/post/search/:query',(req,res) => {
let resultsFromQuery = [];
User.find({'post.title':req.params.query'}, (err,user) => {
user.posts.forEach((post) => {
if(post.title === req.params.query){
resultsFromQuery.push(post);
}
})
})
res.send(JSON.stringify(resultsFromQuery))
})
EDIT: Here is my schema's.
User Schema (Parent)
const mongoose = require('mongoose'),
Schema = mongoose.Schema,
PostSchema = require('./post.js');
let UserSchema = new Schema({
username: {
type: String,
required: true,
unique: true
},
password: {
type: String,
required: true
},
posts: [PostSchema]
})
module.exports = mongoose.model('User',UserSchema);
Post Schema (Child)
const mongoose = require('mongoose'),
Schema = mongoose.Schema;
let PostSchema = new Schema({
title: {
type: String
},
description: {
type: String
},
image: {
type: String
},
original_poster: {
id: {
type: String,
required: true
},
username: {
type: String,
required: true
}
},
tags: {
type: [String],
required: true
}
})
module.exports = PostSchema;
EDIT:
Here is a sample document
the result of db.users.find({username: 'john'})
{
"_id" : ObjectId("5a163317bf92864245250cf4"),
"username" : "john",
"password" : "$2a$10$mvE.UNgvBZgOURAv28xyA.UdlJi4Zj9IX.OIiOCdp/HC.Cpkuq.ru",
"posts" : [
{
"_id" : ObjectId("5a17c32d54d6ef4987ea275b"),
"title" : "Dogs are cool",
"description" : "I like huskies",
"image" : "https://media1.giphy.com/media/EvRj5lfd8ctUY/giphy.gif",
"original_poster" : {
"id" : "5a163317bf92864245250cf4",
"username" : "john"
},
"tags" : [
"puppies",
"dogs"
]
}
],
"__v" : 1
}

Answer 1

Yes you can find directly the post title from the user model. like bellow
User.find({"posts.title": "Cats are cool"}, (err, users) => {
if(err) {
// return error
}
return res.send(users)
})
That will return user with all post not only the matching post title. So to return only matching post title can use $ positional operator. like this query
User.find({"posts.title": "Cats are cool"},
{username: 1, "posts.$": 1}, // add that you need to project
(err, users) => {
if(err) {
// return error
}
return res.send(users)
})
that only return matching post

Answer 2

Since you are saving OP data, why not do:
// you'll need to adapt how your are getting the user-id here
const { user } = req
Post.find({ title: 'the title', 'original_poster.id': user.id }, (err, posts) => {
console.log(posts); })
Though I would advise you to adjust your Post-schema:
original_poster: {
type: Schema.Types.ObjectId,
ref: 'User'
}
},
Then you can do Post.find({}).populate('original_poster') to include it in your results.!