I've got two relations in my Mongoose/MongoDB-Application:
USER:
{
name: String,
items: [{ type: mongoose.Schema.ObjectId, ref: 'Spot' }]
}
and
ITEM
{
title: String,
price: Number
}
As you can see, my user-collection containing a "has-many"-relation to the item-collection.
I'm wondering how to get all Items which are mentioned in the items-field of on specific user.
Guess its very common question, but I haven't found any solution on my own in the Docs or elsewhere. Can anybody help me with that?
If you are Storing items reference in user collection,then fetch all items from user,it will give you a array of object ids of items and then you can access all items bases on their ids
var itemIdsArray = User.items;
Item.find({
'_id': { $in: itemIdsArray}
}, function(err, docs){
console.log(docs);
});
You can get the items at the same time you query for the user, by using Mongoose's support for population:
User.findOne({_id: userId}).populate('items').exec(function(err, user) {
// user.items contains the referenced docs instead of just the ObjectIds
});
Related
The schema is like this. it's a shopping cart with items:
export interface Cart extends mongoose.Document {
userId: string;
total: number;
count: number;
status: string;
items: [
{
itemId: string;
itemName: string;
count: number;
price: number;
itemTotal: number;
},
];
}
if you look at the mondodb data, there is an _id to each of the members in items array.
I have this _id, and i want to remove an item by that _id.
The problem is, it's typescript, and _id is not part of the schema.
Here is the code i use to delete an item:
const cart = await this.cartModel.findOneAndUpdate(
{ _id: dto.cartId },
{ $pull: { items: { _id: '1234567890' } } },
{ new: true },
);
Which means, in that specific cart, find the item with _id equals to 1234567890, and delete it.
BUT the _id has red squiggly, as it is not part of my schema.
How can I solve this?
It shoulds be id not _id. Because _id is an object. But our query cannot send object to params. So, it should be a hexString.
You can change your entity _id to id by:
#ObjectIdColumn()
#Transform(id => id.toString())
id: string;
So that, you can use id as hexString anywhere. Hope it helps
For lack of better solution, i have bypassed this issue by adding a text field called timeStamp. when an item is added to the cart, i push the current time (in ms) to that field, and that is unique enough to distinguish between entries in a shopping cart. In case you wonder, itemId is not good enough, as people can have the same item in 2 or more lines, with different details. I have added of course the new field to my schema, so typescript is not complaining ;)
I'm having a problem that is really bugging me. I don't even want to use this solution I don't think but I want to know if there is one.
I was creating a comment section with mongodb and mongoose and keeping the comments attached to the resource like this:
const MovieSchema = new mongoose.Schema({
movieTitle: {type: String, text: true},
year: Number,
imdb: String,
comments: [{
date: Date,
body: String
}]
})
When editing the comments body I understood I could access a nested document like this:
const query = {
imdb: req.body.movie.imdb,
"comments._id": new ObjectId(req.body.editedComment._id)
}
const update = {
$set: {
"comments.$.body": req.body.newComment
}
}
Movie.findOneAndUpdate(query, update, function(err, movie) {
//do stuff
})
I then wanted to roll out a first level reply to comments, where every reply to a comment or to another reply just appeared as an array of replies for the top level comment (sort of like Facebook, not like reddit). At first I wanted to keep the replies attached to the comments just as I had kept the comments attachted to the resource. So the schema would look something like this:
const MovieSchema = new mongoose.Schema({
movieTitle: {type: String, text: true},
year: Number,
imdb: String,
comments: [{
date: Date,
body: String,
replies: [{
date: Date,
body: String
}]
}]
})
My question is how would you go about accessing a nested nested document. For instance if I wanted to edit a reply it doesn't seem I can use two $ symbols. So how would I do this in mongodb, and is this even possible?
I'm pretty sure I'm going to make Comments have its own model to simplify things but I still want to know if this is possible because it seems like a pretty big drawback of mongodb if not. On the other hand I'd feel pretty stupid using mongodb if I didn't figure out how to edit a nested nested document...
according to this issue: https://jira.mongodb.org/browse/SERVER-27089
updating nested-nested elements can be done this way:
parent.update({},
{$set: {“children.$[i].children.$[j].d”: nuValue}},
{ arrayFilters: [{ “i._id”: childId}, { “j._id”: grandchildId }] });
this is included in MongoDB 3.5.12 development version, in the MongoDB 3.6 production version.
according to https://github.com/Automattic/mongoose/issues/5986#issuecomment-358065800 it's supposed to be supported in mongoose 5+
if you're using an older mongodb or mongoose versions, there are 2 options:
find parent, edit result's grandchild, save parent.
const result = await parent.findById(parentId);
const grandchild = result.children.find(child => child._id.equals(childId))
.children.find(grandchild => grandchild._id.equals(grandchildId));
grandchild.field = value;
parent.save();
know granchild's index "somehow", findByIdAndUpdate parent with:
parent.findByIdAndUpdate(id,
{ $set: { [`children.$.children.${index}.field`]: value }});
I am trying to update my collection which has an array field(initially blank) and for this I am trying this code
Industry.update({_id:industryId},
{$push:{categories: id:categoryId,
label:newCategory,
value:newCategory }}}});
No error is shown, but in my collection just empty documents({}) are created.
Note: I have both categoryId and newCategory, so no issues with that.
Thanks in advance.
This is the schema:
Industry = new Meteor.Collection("industry");
Industry.attachSchema(new SimpleSchema({
label:{
type:String
},
value:{
type:String
},
categories:{
type: [Object]
}
}));
I am not sure but maybe the error is occuring because you are not validating 'categories' in your schema. Try adding a 'blackbox:true' to your 'categories' so that it accepts any types of objects.
Industry.attachSchema(new SimpleSchema({
label: {
type: String
},
value: {
type: String
},
categories: {
type: [Object],
blackbox:true // allows all objects
}
}));
Once you've done that try adding values to it like this
var newObject = {
id: categoryId,
label: newCategory,
value: newCategory
}
Industry.update({
_id: industryId
}, {
$push: {
categories: newObject //newObject can be anything
}
});
This would allow you to add any kind of object into the categories field.
But you mentioned in a comment that categories is also another collection.
If you already have a SimpleSchema for categories then you could validate the categories field to only accept objects that match with the SimpleSchema for categories like this
Industry.attachSchema(new SimpleSchema({
label: {
type: String
},
value: {
type: String
},
categories: {
type: [categoriesSchema] // replace categoriesSchema by name of SimpleSchema for categories
}
}));
In this case only objects that match categoriesSchema will be allowed into categories field. Any other type would be filtered out. Also you wouldnt get any error on console for trying to insert other types.(which is what i think is happening when you try to insert now as no validation is specified)
EDIT : EXPLANATION OF ANSWER
In a SimpleSchema when you define an array of objects you have to validate it,ie, you have to tell it what objects it can accept and what it can't.
For example when you define it like
...
categories: {
type: [categoriesSchema] // Correct
}
it means that objects that are similar in structure to those in another SimpleSchema named categoriesSchema only can be inserted into it. According to your example any object you try to insert should be of this format
{
id: categoryId,
label: newCategory,
value: newCategory
}
Any object that isn't of this format will be rejected while insert. Thats why all objects you tried to insert where rejected when you tried initially with your schema structured like this
...
categories: {
type: [Object] // Not correct as there is no SimpleSchema named 'Object' to match with
}
Blackbox:true
Now, lets say you don't what your object to be filtered and want all objects to be inserted without validation.
Thats where setting "blackbox:true" comes in. If you define a field like this
...
categories: {
type: [Object], // Correct
blackbox:true
}
it means that categories can be any object and need not be validated with respect to some other SimpleSchema. So whatever you try to insert gets accepted.
If you run this query in mongo shell, it will produce a log like matched:1, updated:0. Please check what you will get . if matched is 0, it means that your input query is not having any matching documents.
I have a Collection that has documents with an array of nested objects.
Here is fixture code to populate the database:
if (Parents.find().count() == 0) {
var parentId = Parents.insert({
name: "Parent One"
});
Children.insert({
parent: parentId,
fields: [
{
_id: new Meteor.Collection.ObjectID(),
position: 3,
name: "three"
},
{
_id: new Meteor.Collection.ObjectID(),
position: 1,
name: "one"
},
{
_id: new Meteor.Collection.ObjectID(),
position: 2,
name: "two"
},
]
});
}
You might be asking yourself, why do I even need an ObjectID when I can just update based off of the names. This is a simplified example to a much more complex schema that I'm currently working on and the the nested object are going to be created dynamically, the ObjectID's are definitely going to be necessary to make this work.
Basically, I need a way to save those nested objects with a unique ID and be able to update the fields by their _id.
Here is my Method, and the call I'm making from the browser console:
Meteor.methods({
upChild: function( options ) {
console.log(new Meteor.Collection.ObjectID());
Children.update({_id: options._id, "fields._id": options.fieldId }, {$set: {"fields.$.position": options.position}}, function(error){
if(error) {
console.log(error);
} else {
console.log("success");
}
});
}
});
My call from the console:
Meteor.call('upChild', {
_id: "5NuiSNQdNcZwau92M",
fieldId: "9b93aa1ef3868d762b84d2f2",
position: 1
});
And here is a screenshot of the html where I'm rendering all of the data for the Parents and Children collections:
Just an observation, as I was looking how generate unique IDs client side for a similar reason. I found calling new Meteor.Collection.ObjectID() was returning a object in the form 'ObjectID("abc...")'. By assigning Meteor.Collection.ObjectID()._str to _id, I got string as 'abc...' instead, which is what I wanted.
I hope this helps, and I'd be curious to know if anyone has a better way of handling this?
Jason
Avoid using the _str because it can change in the future. Use this:
new Meteor.Collection.ObjectID().toHexString() or
new Meteor.Collection.ObjectID().valueOf()
You can also use the official random package:
Random.id()
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) );