I try to play with populate but without success ...
It's possible to do this?
I have 2 shema :
- User
import mongoose, { Schema } from 'mongoose'
const userSchema = new Schema({
email: { type: String, unique: true },
password: String,
passwordResetToken: String,
passwordResetExpires: Date,
products: [{
productId: { type: Schema.Types.ObjectId, ref: 'Product' },
dateAdd: { type: Date, default: Date.now }
}]
}, { timestamps: true })
const User = mongoose.model('User', userSchema)
export default User
And Product :
import mongoose, { Schema } from 'mongoose'
const productSchema = new Schema({
domain: String,
originUrl: { type: String },
price: Number,
img: String,
userFollow: [{ type: Schema.Types.ObjectId, ref: 'User' }]
})
const Product = mongoose.model('Product', productSchema)
export default Product
So I want to retrieve all the info for each of my prodcutId
I try this way (and many others without success):
User.findOne({ _id: userId }).populate({
path: 'products.productId',
populate: { path: 'products.productId', model: 'Products' }
}).exec(function (err, products) {
if (err) {
console.log('errors :' + err)
}
console.log('Product => ' + util.inspect(products))
})
Populate has no effect, same result with just the findOne()
I think User.findOne({ _id: userId }).populate('products.productId') should work.
Try using aggregate function of MongoDB and $lookup.
Users.aggregate([
{
"$match":
{
_id: user.id
}
},
{
"$lookup":
{
from: "Product",
localField: "products",
foreignField: "_id",
as: "products"
}
}
])
.exec()
.then((result) => {
//your result
})
.catch((err) => {
// if any error
});
Related
I cannot fetch users data from Mongo when I use populate() method for posts of users.
router.get("/users", (req, res) => {
User.find()
.populate("posts")
.exec()
.then((users) => {
res.json({ users });
})
.catch((err) => console.log(err));
});
Mongo Schema
const mongoose = require("mongoose");
const Schema = mongoose.Schema;
const { ObjectId } = mongoose.Schema.Types;
const Post = require("../models/Post");
const UserSchema = new Schema({
name: {
type: String,
required: true
},
username: {
type: String,
requied: true
},
userimg: {
type: String
},
followers: [
{
type: ObjectId,
ref: "User"
}
],
following: [
{
type: ObjectId,
ref: "User"
}
],
posts: [
{
type: ObjectId,
ref: "Post"
}
],
email: {
type: String,
required: true
},
password: {
type: String,
required: true
},
date: {
type: Date,
default: Date.now
}
});
module.exports = User = mongoose.model("users", UserSchema);
When I remove .populate("posts") than I get 200 Success status and users data but without popoulation of referred posts from the posts collection.
So i'll be doing a little modification to your model file
const mongoose = require("mongoose");
const Schema = mongoose.Schema;
const Post = require("../models/Post");
const UserSchema = new Schema({
name: {
type: String,
required: true
},
username: {
type: String,
requied: true
},
userimg: {
type: String
},
followers: [
{
type: Schema.Types.ObjectId,
ref: "User"
}
],
following: [
{
type: Schema.Types.ObjectId,
ref: "User"
}
],
posts: [
{
type: Schema.Types.ObjectId,
ref: "Post"
}
],
email: {
type: String,
required: true
},
password: {
type: String,
required: true
},
date: {
type: Date,
default: Date.now
}
});
module.exports = User = mongoose.model("User", UserSchema);
Can you change your exec() to execPopulate()
router.get("/users", (req, res) => {
User.find()
.populate("posts")
.execPopulate()
.then((users) => {
res.json({ users });
})
.catch((err) => console.log(err));
});
Thank you all for your help. I found the error:
ref: "posts" instead of ref: "Post"
ref: "users" instead of ref: "User"
Here's my Mongoose schema:
const productSchema = mongoose.Schema({
writer: {
type: Schema.Types.ObjectId,
ref: 'User'
},
schedule: [{
dateTime: {
type: String,
unique: 1
},
candidates: [{
type: Schema.Types.ObjectId,
ref: 'User'
}],
attorn: {
type: Schema.Types.ObjectId,
ref: 'User'
}
}]
...
This is where I get my items along with the candidates:
Product.find({ '_id': { $in: productIds } })
.populate('writer')
.populate({
path: 'schedule',
populate: {
path: 'candidates',
model: 'User'
}
})
.exec((err, product) => {
if (err) return res.status(400).send(err)
return res.status(200).send(product)
})
Result of this code is a product with only populated 'writer' and empty array for 'candidates'
If I remove the line for populating 'candidates', it returns array of _id for 'candidates'
How do I populate the 'candidates' array?
can you try this
Product.find({ _id: { $in: productIds } })
.populate("writer")
.populate({
path: "schedule.candidates",
})
.populate({
path: "schedule.attorn",
})
.exec((err, product) => {
if (err) return res.status(400).send(err);
return res.status(200).send(product);
});
I have two schema's Role and User. When I do a Role.find() I want to populate the users with the users that have that specific role.
let roleSchema = new Schema({
name: {
type: String,
required: true,
},
...,
users: [{
type: mongoose.Schema.ObjectId,
ref: 'User'
}]
}, {
timestamps: true,
});
const Role = mongoose.model('Role', roleSchema);
let userSchema = new Schema({
username: {
type: String,
required: true,
},
...,
role: {
type: mongoose.Schema.ObjectId,
ref: 'Role'
},
}, {
timestamps: true,
}
);
const User = mongoose.model('User', userSchema);
When I get the Role with the following code:
Role.findById(req.params.roleId)
.populate('users')
.then(role => {
res.send(role);
}).catch(err => {
res.send(err)
});
It returns the following:
{
"users": [
],
"_id":"5c78006df35ca926534ad865",
"name":"Role",
"createdAt":"2019-02-28T15:38:21.741Z",
"updatedAt":"2019-02-28T15:38:21.741Z",
"__v":0
}
User.find().populate('role') works just fine, but Role.find().populate('users') doesn't.
Am I doing something wrong or don't I need .populate() in this case?
Nevermind. I think I had to use aggregate().lookup() for that all along... since there weren't any ids in Role.users...
Role.aggregate()
.lookup({
from: 'users',
localField: '_id',
foreignField: 'role',
as: 'users'
}).then( role => {
res.send(role);
});
This gave me the response I wanted.
I'm new to Mongoose I don't know how to populate on condition.
So this is my model :
const OrderSchema = new Schema({
products: [{ type: Schema.Types.ObjectId, ref: 'Product' }],
remarks: {type: String, lowercase: true}
});
mongoose.model("Order", OrderSchema);
const ProductSchema = new Schema({
reference: {type: String}
status: {type: Schema.Types.ObjectId, ref: 'ProductStatus'}
});
mongoose.model("Product", ProductSchema);
const ProductStatus = new Schema({
name: {type: String}
});
const CountrySchema = new Schema({
name: {type: String}
});
mongoose.model("Country", CountrySchema);
I have a getOrderById methods
export const getOrderById = async (req, res) => {
let id = req.params.id;
try {
await orderModel
.findById(id)
.populate({
path: 'products',
populate: {
path: 'country',
model: 'Country'
}
})
.populate({
path: 'products',
populate: {
path: 'status',
model: 'ProductStatus'
}
})
.exec(function (err, orders) {
if (err) {
res.send(err);
}
res.status(200).json(orders);
});
} catch (error) {
console.log(error);
}
}
And now I would like to show in the order lists all products that have the status Received in France.
First, I guess you also missed reference to the country in the product schema, so assuming these are your corrected schemas:
const OrderSchema = new Schema({
products: [{
type: Schema.Types.ObjectId,
ref: 'Product'
}],
remarks: {
type: String,
lowercase: true
}
});
const Order = mongoose.model("Order", OrderSchema);
const ProductSchema = new Schema({
reference: {
type: String
},
country: {
type: Schema.Types.ObjectId,
ref: 'Country'
},
status: {
type: Schema.Types.ObjectId,
ref: 'ProductStatus'
}
});
const Product = mongoose.model("Product", ProductSchema);
const ProductStatusSchema = new Schema({
name: {
type: String
}
});
const ProductStatus = mongoose.model("ProductStatus", ProductStatusSchema);
const CountrySchema = new Schema({
name: {
type: String
}
});
const Country = mongoose.model("Country", CountrySchema);
As far as I understand you want to only show the products, whose country's name is 'France' and ProductStatus' name is 'Received', these kind of operations are done through Aggregation
Your query may look like this assuming you want to do it one query:
const getOrderById = async (req, res) => {
let id = req.params.id.toString();
const ObjectId = mongoose.Types.ObjectId
try {
const aggregationStages = [{
$match: {
_id: ObjectId(id) //It is important to cast to ObjectId in aggregations
}
}, {
$lookup: {
from: 'products',
let: {
productIds: '$products'
},
pipeline: [{
$match: {
$expr: {
$in: ['$_id', '$$productIds']
}
}
}, {
$lookup: {
from: 'countries',
localField: 'country',
foreignField: '_id',
as: 'country'
}
}, {
$lookup: {
from: 'productstatuses',
localField: 'status',
foreignField: '_id',
as: 'status'
}
}, {
$match: {
'country.name': 'France',
'status.name': 'Received'
}
}],
as: 'products'
}
}];
await orderModel.aggregate(aggregationStages)
.exec(function (err, orders) { // The return is an array btw.
if (err) {
res.send(err);
}
res.status(200).json(orders);
});
} catch (error) {
console.log(error);
}
}
If you feel the aggregation is complicated you may resort to breaking it to smaller simpler queries. Feel free to ask if you need more explanation/modification.
It's possible that i'm just burned out, but I have the following models:
user
const mongoose = require('mongoose');
const validate = require('mongoose-validator');
const Post = require('./post');
let UserSchema = mongoose.Schema({
firstName: { type: String, required: true },
lastName: { type: String, required: true },
email: {
type: String, required: true, lowercase: true, trim: true, unique: true, index: true,
validate: [validate({ validator: 'isEmail', message: 'Invalid Email!' })]
},
posts: [{ type: mongoose.Schema.Types.ObjectId, ref: 'Post' }]
})
module.exports = mongoose.model('User', UserSchema);
posts
const _ = require('lodash');
const mongoose = require('mongoose');
const User = require('./user');
let PostSchema = mongoose.Schema({
user: { type: mongoose.Schema.Types.ObjectId, ref: 'User', required: true },
title: { type: String, required: true },
body: { type: String, require: true }
})
PostSchema.post('save', async function (next) {
await User.update({ _id: this.user }, { $push: { posts: this._id } })
return next();
})
module.exports = mongoose.model('Post', PostSchema);
When trying to add a new post, the post save hook runs, but I get the error User.update is not a function (same goes for findOneAndUpdate, findOne, etc).
I can call user.update from the rest of the app without issues, so not sure whats happening here. Both models are in the same directory.
What you missed is that post middleware has the first argument as the "document" and not the next handler:
user.js
const { Schema } = mongoose = require('mongoose');
const userSchema = new Schema({
firstName: String,
lastName: String,
posts: [{ type: Schema.Types.ObjectId, ref: 'Post' }]
});
post.js
const { Schema } = mongoose = require('mongoose');
const User = require('./user');
const postSchema = new Schema({
user: { type: Schema.Types.ObjectId, ref: 'User' },
title: String,
body: String
});
// note that first argument is the "document" as in "post" once it was created
postSchema.post('save', async function(doc, next) {
await User.update({ _id: doc.user._id },{ $push: { posts: doc._id } });
next();
});
index.js
const { Schema } = mongoose = require('mongoose');
const User = require('./user');
const Post = require('./post');
const uri = 'mongodb://localhost/posttest';
mongoose.set('debug', true);
mongoose.Promise = global.Promise;
const log = data => console.log(JSON.stringify(data, undefined, 2));
(async function() {
try {
const conn = await mongoose.connect(uri);
await Promise.all(Object.entries(conn.models).map(([k,m]) => m.remove()));
let user = await User.create({ firstName: 'Ted', lastName: 'Logan' });
let post = new Post({ user: user._id, title: 'Hi', body: 'Whoa!' });
post = await post.save();
mongoose.disconnect();
} catch(e) {
console.error(e)
} finally {
process.exit()
}
})()
Returns:
Mongoose: users.remove({}, {})
Mongoose: posts.remove({}, {})
Mongoose: users.insertOne({ posts: [], _id: ObjectId("5b0217001b5a55208150cc9b"), firstName: 'Ted', lastName: 'Logan', __v: 0 })
Mongoose: posts.insertOne({ _id: ObjectId("5b0217001b5a55208150cc9c"), user: ObjectId("5b0217001b5a55208150cc9b"), title: 'Hi', body: 'Whoa!', __v: 0 })
Mongoose: users.update({ _id: ObjectId("5b0217001b5a55208150cc9b") }, { '$push': { posts: ObjectId("5b0217001b5a55208150cc9c") } }, {})
Showing that the update fires with the correct detail.
In good design you really should avoid this and simply drop the posts array from the User model. You can always either use a virtual instead:
userSchema.virtual('posts', {
ref: 'Post',
localField: '_id',
foreignField: 'user'
})
Or just get the data via $lookup:
User.aggregate([
{ "$match": { "_id": userId } }
{ "$lookup": {
"from": Post.collection.name,
"localField": "_id",
"foreignField": "user",
"as": "posts"
}}
])
Storing and maintaining arrays of related ObjectId values "on the parent" is kind of an "anti-pattern" and leads to unnecessary overhead such as writing in two places where you only need "one".
Also in general you should be opting for embedding "first", and only considering "referencing" if and when the usage pattern of the application actually demands it. Simply copying the same patterns of an RDBMS with a database engine that was not designed for that is not the best way to utilize it.