If a user has an array called "tags":
var User = new Schema({
email: {
type: String,
unique: true,
required: true
},
tags: [{
type: mongoose.Schema.Types.ObjectId,
ref:'Tag',
required: true
}],
created: {
type: Date,
default: Date.now
}
});
and I do a populate('tags') on a query:
User.findById(req.params.id)
.populate("tags")
.exec(function(err, user) { ... });
If one of the tags in the list has actually been deleted, is there a way to remove this dead reference in "tags"?
Currently, the returned user object IS returning the desired result -- ie. only tags that actually exist are in the tags array... however, if I look at the underlying document in mongodb, it still contains the dead tag id in the array.
Ideally, I would like to clean these references up lazily. Does anyone know of a good strategy to do this?
I've tried to find some built-in way to do that but seems that mongoose doesn't provide such functionality.
So I did something like this
User.findById(userId)
.populate('tags')
.exec((err, user) => {
user.tags = user.tags.filter(tag => tag != null);
res.send(user); // Return result as soon as you can
user.save(); // Save user without dead refs to database
})
This way every time you fetch user you also delete dead refs from the document. Also, you can create isUpdated boolean variable to not call user.save if there was no deleted refs.
const lengthBeforeFilter = user.tags.length;
let isUpdated = user.tags.length;
user.tags = user.tags.filter(tag => tag != null);
isUpdated = lengthBeforeFilter > user.tags.length;
res.send(user);
if (isUpdated) {
user.save();
}
Assuming you delete these tags via mongoose, you can use the post middleware.
This will be executed after you've deleted a tag.
tagSchema.post('remove', function(doc) {
//find all users with referenced tag
//remove doc._id from array
});
its sample retainNullValues: true
Example:
User.findById(req.params.id)
.populate({
path: "tag",
options: {
retainNullValues: true
}
})
Related
I'm working on a project that is basically a super watered down social media website.
I have a chunk done already, but I'm having some issues creating a put request to my mongodb. Basically, I want to send a put request to update a numeric value to be able to have a like counter on each post.
What I'm trying do here is send a put request with a specific post id. I'm storing the post id in a hidden text box to reference it. This is pug formatted HTML:
input.form-control(type='hidden' value=item.id id='postId' placeholder='' name='postId' required='false')
form(method='PUT' action='/update/{{post._id}}')
button(type='submit') Like
Then in my router.js file I'm basically trying to take in that id and set the likes field in the Post schema to 1 (just for testing).
router.put('/update/:id', function (req, res, next) {
let id = {
_id: ObjectID(req.params.id)
};
Post.update({_id: id}, {$set:{'likes': 1}}, (err, result) => {
if(err) {
throw err;
}
res.send('user updated sucessfully');
});
});
Here is my post schema
var mongoose = require("mongoose");
var PostSchema = new mongoose.Schema({
postText: {
type: String,
unique: false,
required: true,
trim: true
},
usernameText: {
type: String,
unique: false,
required: true,
trim: true
},
likes:{
type: Number,
unique: false,
required: false
}
});
var Post = mongoose.model("Posts", PostSchema);
module.exports = Post;
Any and all help would be highly appreciated, thank you
You can't change the ObjectId. The ObjectId is generated by MongoDB and can't be changed by the user using query functions.
If you want to assign a unique id to each user for example, then create a separate field in your schema.
You cannot change the ID
'PUT' method is not supported directly as far as I know. You need method override
My JSON response contains a field first_name but I want my Mongoose model to represent this field as firstName. Is this possible and if so then how?
You can create a new object with different property names from the one Mongoose returns. A nice way of doing this is to create a transform function. For example, let's say this is your schema:
{
firstName: { type: String, required: true },
lastName: { type: String, required: true }
}
Then you can use this function to create a new object with the desired property names:
function transformDocument (doc) {
return {
first_name: doc.firstName,
last_name: doc.lastName
}
}
Then, when you query the DB, you apply this function to the response:
Person.findOne({ firstName: 'John', lastName: 'Smith' })
.then(transformDocument)
Doug W has a good solution, but if you don't want to be using Promises and chaining .thens, then you can simply add options to the schema like this:
const mongoose = require ('mongoose'); // I am using v5.9.1 at the moment
const { Schema } = mongoose.Schema;
// Specify an options object
const options = {
toJSON: {
versionKey: false
}
// If you ever send the query result as an object,
// you may remove it from there, too, if you wish
// toObject: {
// versionKey: false
// }
};
// Attach the options object to the schema by
// passing it into Schema as the second argument
const mySchema = new Schema({
/** define your schema */
}, options);
This will still save __v to the document in the database. But it will not appear on the json/object when it is the result of a mongoose query.
Besides setting versionKey: false in the options, you may also specify a transform function:
/* ... */
// Specify an options object
const options = {
toJSON: {
// versionKey: false,
transform: function(doc, ret) {
// ret is the object that will be returned as the result
// (and then stringified before being sent)
delete ret.__v;
return ret;
}
}
};
/* ... */
I know this question is nearly two years old, but I needed an answer to this question, and google was not kind to me at the time. I figured it out, and now I'm hoping someone else will be looking for an answer here and find that they have options. Pun not originally intended.
I have following mongoose model and routing file.
user.js
var mongoose = require('mongoose'),
Schema = mongoose.Schema,
ObjectId = Schema.ObjectId,
var userSchema = new Schema({
nick_name: {
type: String,
unique: true
},
email: {
type: String,
unique: true
},
first_name: String,
last_name: String,
birth_date: {
type: Date
},
password: {
type: String,
select: true
},
user_type: {
type: Number,
},
is_active: {
type: Number,
default: -1
}
}, { collection: 'user' });
/*
*Validations
*/
userSchema.path('nick_name').required(true, 'nick name is required!');
userSchema.path('email').required(true, 'email is required!');
userSchema.path('password').required(true, 'password is required!');
userSchema.path('user_type').required(true, 'user type is required!');
userSchema.path('is_active').required(true, 'is active is required!');
userSchema.path('is_close').required(true, 'is close is required!');
userSchema.path('first_name').required(true, 'first name is required!');
userSchema.path('last_name').required(true, 'last name is required!');
userSchema.path('birth_date').required(true, 'birth date is required!');
var User = module.exports = mongoose.model("User", userSchema);
router.js
var express = require('express');
var router = express.Router();
var User = require('../models/user');
router
.route('/api/user/register')
.post(
function(req, res, next) {
var user_ = new User(req.body);
/*
*here all validations are required
*/
user_.validate(function(err) {
if (err) {
res.json({ "status": 0, "error": err });
} else {
user_.save(function(err) {
if (err) {
res.json({ "status": 0, "error": { "other": "Oops! something went wrong, please try again later." } });
} else {
res.json({ error: 1, message: 'User registered' });
}
});
}
}
});
}
});
In above routing file I can validate all fields by using validate() method but, I have need validation as following conditions
->When user register, following fields are required
nick_name
email
password
user_type
is_active
->When user edit his profile (after register), all fields are required.
Can anybody help me to solve this issue ?
I just found myself in this situation, want to update a comment model and want a specific field validation for field 'content'.
Im thinking about a hack, pull off that full comment document from the database, then create a new schema object with the same properties from the comment document that i just pulled off from the database and validate this document model copy as if i were to create a new document, but i wont, i wont use the save() method. If there is an error with the 'content' field, which is the only one i care, i would know after validation, if there is no errors then i forget about that new object schema copy that i created by pulling off the comment document from the database, ill forget about it since i already know my 'content' field is valid since no errors where shown, so ill proceed with my flow.
Perhaps instead of pulling off that document from the database i can just create a new object with some fake but valid fields... Then pass the real value i want to test which in my case is 'content', i wouldnt fake that value since i already have it.
NOTE: my comment model has property 'createdAt' so i would replace that for the current date, cause i could have errors at validation saying new comment must be from current date and no from past dates, but since i wont be saving that new date to the database i can add the current date, recall that i will forget about that new object, i wont save it to the database, all i care is the 'content' field validation and see if there is any errors.
I had a Tag schema (defined with mongoose):
var Tag = new Schema({
_id: String // Not ObjectId but the name of the tag.
});
I want to use the tag name as its _id, but I don't want to operate this field with name _id. For example, I would like to add a new tag with code new Tag({name: 'tagA'}) instead of new Tag({_id: 'tagA'}). Since the code is more expressive in this way.
So I need to change name to _id. One method would be using the pre-save hook.
Tag.pre('save', function(next) {
if (!this._id && this.name) this._id = this.name;
next();
});
Are there ways better than this one?
This seems to be the best option I found with mongoose for implementing custom primary keys.
<schemaToHook>.pre('save', true, function(next, done) {
// trigger next middleware in parallel
next();
if (!this._id && this.name) {
this._id = this.name;
}
done();
});
I am using a parallel middleware and expecting better performance. Also, while using the above implementation you might want to consider using findOneAndUpdate with upsert = true for INSERT or REPLACE equivalent implementation.
MyModel.findOneAndUpdate(
{foo: 'bar'}, // find a document with that filter
modelDoc, // document to insert when nothing was found
{upsert: true, new: true, runValidators: true}, // options
function (err, doc) { // callback
if (err) {
// handle error
} else {
// handle document
}
}
);
I'm using MongoDB as a log keeper for my app to then sync mobile clients. I have this models set up in NodeJS:
var UserArticle = new Schema({
date: { type: Number, default: Math.round((new Date()).getTime() / 1000) }, //Timestamp!
user: [{type: Schema.ObjectId, ref: "User"}],
article: [{type: Schema.ObjectId, ref: "Article"}],
place: Number,
read: Number,
starred: Number,
source: String
});
mongoose.model("UserArticle",UserArticle);
var Log = new Schema({
user: [{type: Schema.ObjectId, ref: "User"}],
action: Number, // O => Insert, 1 => Update, 2 => Delete
uarticle: [{type: Schema.ObjectId, ref: "UserArticle"}],
timestamp: { type: Number, default: Math.round((new Date()).getTime() / 1000) }
});
mongoose.model("Log",Log);
When I want to retrive the log I use the follwing code:
var log = mongoose.model('Log');
log
.where("user", req.session.user)
.desc("timestamp")
.populate("uarticle")
.populate("uarticle.article")
.run(function (err, articles) {
if (err) {
console.log(err);
res.send(500);
return;
}
res.json(articles);
As you can see, I want mongoose to populate the "uarticle" field from the Log collection and, then, I want to populate the "article" field of the UserArticle ("uarticle").
But, using this code, Mongoose only populates "uarticle" using the UserArticle Model, but not the article field inside of uarticle.
Is it possible to accomplish it using Mongoose and populate() or I should do something else?
Thank you,
From what I've checked in the documentation and from what I hear from you, this cannot be achieved, but you can populate the "uarticle.article" documents yourself in the callback function.
However I want to point out another aspect which I consider more important. You have documents in collection A which reference collection B, and in collection B's documents you have another reference to documents in collection C.
You are either doing this wrong (I'm referring to the database structure), or you should be using a relational database such as MySQL here. MongoDB's power relies in the fact you can embed more information in documents, thus having to make lesser queries (having your data in a single collection). While referencing something is ok, having a reference and then another reference doesn't seem like you're taking the full advantage of MongoDB here.
Perhaps you would like to share your situation and the database structure so we could help you out more.
You can use the mongoose-deep-populate plugin to do this. Usage:
User.find({}, function (err, users) {
User.deepPopulate(users, 'uarticle.article', function (err, users) {
// now each user document includes uarticle and each uarticle includes article
})
})
Disclaimer: I'm the author of the plugin.
I faced the same problem,but after hours of efforts i find the solution.It can be without using any external plugin:)
applicantListToExport: function (query, callback) {
this
.find(query).select({'advtId': 0})
.populate({
path: 'influId',
model: 'influencer',
select: { '_id': 1,'user':1},
populate: {
path: 'userid',
model: 'User'
}
})
.populate('campaignId',{'campaignTitle':1})
.exec(callback);
}
Mongoose v5.5.5 seems to allow populate on a populated document.
You can even provide an array of multiple fields to populate on the populated document
var batch = await mstsBatchModel.findOne({_id: req.body.batchId})
.populate({path: 'loggedInUser', select: 'fname lname', model: 'userModel'})
.populate({path: 'invoiceIdArray', model: 'invoiceModel',
populate: [
{path: 'updatedBy', select: 'fname lname', model: 'userModel'},
{path: 'createdBy', select: 'fname lname', model: 'userModel'},
{path: 'aircraftId', select: 'tailNum', model: 'aircraftModel'}
]});
how about something like:
populate_deep = function(type, instance, complete, seen)
{
if (!seen)
seen = {};
if (seen[instance._id])
{
complete();
return;
}
seen[instance._id] = true;
// use meta util to get all "references" from the schema
var refs = meta.get_references(meta.schema(type));
if (!refs)
{
complete();
return;
}
var opts = [];
for (var i=0; i<refs.length; i++)
opts.push({path: refs[i].name, model: refs[i].ref});
mongoose.model(type).populate(instance, opts, function(err,o){
utils.forEach(refs, function (ref, next) {
if (ref.is_array)
utils.forEach(o[ref.name], function (v, lnext) {
populate_deep(ref.ref_type, v, lnext, seen);
}, next);
else
populate_deep(ref.ref_type, o[ref.name], next, seen);
}, complete);
});
}
meta utils is rough... want the src?
or you can simply pass an obj to the populate as:
const myFilterObj = {};
const populateObj = {
path: "parentFileds",
populate: {
path: "childFileds",
select: "childFiledsToSelect"
},
select: "parentFiledsToSelect"
};
Model.find(myFilterObj)
.populate(populateObj).exec((err, data) => console.log(data) );