I am trying reference another object in a model in node,
User = new Schema({
username: {
type: String,
index: {unique: true}
}
});
Idea = new Schema({
Creator: {
type: User
}
});
but I get this error Undefined type at "creator" Did you try nesting Schemas? You can only nest using refs or arrays. I believe I want to use refs, but could not find documentation on it, can some one help me out. Thanks
I found out the answer to my own question here it is.
User = new Schema({
username: {
type: String,
index: {unique: true}
}
});
Idea = new Schema({
Creator: {
type: Schema.ObjectId,
ref: 'User'
}
});
I'd like to add a reply to this question because it's the first result in Google.
No you can't use Nested Schema as the other replies say. But you can still use the same object in different schema.
// Regular JS Object (Not a schema)
var Address = {
address1: String,
address2: String,
city: String,
postalcode: String
};
var Customer = new Schema({
firstname: String,
lastname: String,
address: Address
});
var Store = new Schema({
name: String,
address: Address
});
That way you can modify the Address Object to make the changes available on all your schemas sharing the object.
Here is link to manual # refs.
Tho You can't use refs at schema design level.
I decided to solve a similar problem for my project by making my subdocument a nested type
Foo = new Schema({
name: String,
bar: {
name: String
}
});
Obviously this will not work if you need Bar to be its own model. Perhaps because you reference it as a model in other objects. In my case this was all I needed to do, but the Subdocuments section of the Mongoose guide does not mention it as an option so I am adding to this discussion.
Related
Take a look at this Schema:
let userSchema = new Schema({
email: { type: String, required: true },
password: { type: String, required: true },
books: [{
cover: String,
title: String,
link: String,
requests: { requestingUser: String, bookOffered: String,
beingRequested: false }
}],
ip: String
});
What I am trying to do is use findOneAndUpdate to (based on given information) find the correct user, and then find the correct book (from the array of books by given title) And update the requests field (which is another object.) Is this possible to accomplish with only one findOneAndUpdate query ?
So far my finding has been that I would have to do a findOne to get the correct user, and then do a findOneAndUpdate nested inside that. Is there a way to do this with one query command?
Thanks
I have a mongoose model that looks something like this
var LogSchema = new Schema({
item: {
type: ObjectId,
ref: 'article',
index:true,
},
});
But 'item' could be referenced from multiple collections. Is it possible to do something like this?
var LogSchema = new Schema({
item: {
type: ObjectId,
ref: ['article','image'],
index:true,
},
});
The idea being that 'item' could be a document from the 'article' collection OR the 'image' collection.
Is this possible or do i need to manually populate?
Question is old, but maybe someone else still looks for similar issues :)
I found in Mongoose Github issues this:
mongoose 4.x supports using refPath instead of ref:
var schema = new Schema({
name:String,
others: [{ value: {type:mongoose.Types.ObjectId, refPath: 'others.kind' } }, kind: String }]
})
In #CadeEmbery case it would be:
var logSchema = new Schema({
item: {type: mongoose.Types.ObjectId, refPath: 'kind' } },
kind: String
})
But I did't try it yet...
First of all some basics
The ref option says mongoose which collection to get data for when you use populate().
The ref option is not mandatory, when you do not set it up, populate() require you to give dynamically a ref to him using the model option.
#example
populate({ path: 'conversation', model: Conversation }).
Here you say to mongoose that the collection behind the ObjectId is Conversation.
It is not possible to gives populate or Schema an array of refs.
Some others Stackoverflow people asked about it.
Soluce 1: Populate both (Manual)
Try to populate one, if you have no data, populate the second.
Soluce 2: Change your schema
Create two link, and set one of them.
var LogSchema = new Schema({
itemLink1: {
type: ObjectId,
ref: 'image',
index: true,
},
itemLink2: {
type: ObjectId,
ref: 'article',
index: true,
},
});
LogSchema.find({})
.populate('itemLink1')
.populate('itemLink2')
.exec()
Dynamic References via refPath
Mongoose can also populate from multiple collections based on the value of a property in the document. Let's say you're building a schema for storing comments. A user may comment on either a blog post or a product.
body: { type: String, required: true },
on: {
type: Schema.Types.ObjectId,
required: true,
// Instead of a hardcoded model name in `ref`, `refPath` means Mongoose
// will look at the `onModel` property to find the right model.
refPath: 'onModel'
},
onModel: {
type: String,
required: true,
enum: ['BlogPost', 'Product']
}
});
const Product = mongoose.model('Product', new Schema({ name: String }));
const BlogPost = mongoose.model('BlogPost', new Schema({ title: String }));
const Comment = mongoose.model('Comment', commentSchema);
I am new to mongo and mongoose. I am trying to create 3 collections Users, Articles and Comments. I want the users documents should contain articles that users have saved. The articles object should have users and comments as embedded objects and comments should have embedded user objects.
I want this to be done using the ids of the individual objects so that I can reduce the loading time, but could not find a suitable way to do so using mongoose. Please suggest how should I proceed with the Schema implementation.
var UserSchema = new mongoose.Schema({
name: String,
email: String,
profilePicture: String,
password: String,
readingList: [articleSchema]
});
var commentsSchema = new mongoose.Schema({
content: String,
votes:{
up:[UserSchema],
down:[UserSchema]
},
comments:[commentsSchema],
timestamp:Date.now
});
var articleSchema = new mongoose.Schema({
title: String,
content: String,
image: String,
votes:{
up: [UserSchema],
down: [UserSchema]
},
comments:[commentsSchema],
timestamp: Date.now
});
What you have is failing because articleSchema isn't defined when you're using it in the UserSchema. Unfortunately, you can reverse the order of defining the schema because they're dependent on each other.
I haven't actually tried this, but based on some quick googling there is a way to create the Schema first and then add the properties.
var UserSchema = new mongoose.Schema();
var CommentsSchema = new mongoose.Schema();
var ArticleSchema = new mongoose.Schema();
UserSchema.add({
name: String,
email: String,
profilePicture: String,
password: String,
readingList: [ArticleSchema]
});
CommentsSchema.add({
content: String,
votes:{
up:[UserSchema],
down:[UserSchema]
},
comments:[CommentsSchema],
timestamp:Date.now
});
ArticleSchema.add({
title: String,
content: String,
image: String,
votes:{
up: [UserSchema],
down: [UserSchema]
},
comments:[CommentsSchema],
timestamp: Date.now
});
I'm building a CRUD-style REST service with Node.js, Express and MongoDB using mongoose. This service is going to allow users of an already existing android application to upload/sync the contents of their individual databases online.
The data model for the already-existing application uses UUIDs (generated in Java) which clashes with the shorter, monotonic MongoDB style _id fields. Because the data model already exists and is populated with data from many users, I cannot convert the source data over to monotonic MongoDB-style _ids. This has left me with 2 options that I can think of: either 1) Make Mongo/Mongoose (or some other ODM) play nicely with full UUIDs instead of the monotonic _ids or 2) add a uuid field to the mongoose model in addition to the _id field and fight the pitfalls of this approach. I'm attempting to choose option #1 and running into issues with ObjectID references.
I originally stumbled upon mongoose-uuid, but unfortunately this isn't working for my use-case properly because it was overwriting my explicitly-set _id value when creating new Mongoose objects. Diving into the plugin code, it assumes that an object is new (by calling checking Mongoose's .isNew value) and thus overwrites the _id with a new uuid. Since I need to retain the original uuid when creating new documents in Mongo, this plugin isn't working for me.
Next, I found a post by Aaron Heckmann, creator of mongoose, on a similar topic. This has been helpful, however I am now encountering the problem where I cannot have my mongoose schemas reference each other by ObjectID, since they technically they are now referencing each other using String `_ids.
Schema example:
var mongoose = require('mongoose');
var uuid = require('node-uuid');
var Schema = mongoose.Schema;
var trackPassSchema = new Schema({
_id: { type: String, default: function genUUID() {
uuid.v1()
}},
//Omitting other fields in snippet for simplicity
vehicle: [
{type: Schema.Types.ObjectId, required: true, ref: 'Vehicle'}
]
});
module.exports = mongoose.model('TrackPass', trackPassSchema);
Referencing schema:
var mongoose = require('mongoose');
var uuid = require('node-uuid');
var Schema = mongoose.Schema;
var vehicleSchema = new Schema({
_id: { type: String, default: function genUUID() {
uuid.v1()
}},
//Omitting other fields in snippet for simplicity
description: {type: String},
year: {type: Number}
});
module.exports = mongoose.model('Vehicle', vehicleSchema);
When I attempt to call save() a trackPass that has been passed in from my application:
var trackPass = new TrackPass(req.body);
//Force the ID to match what was put into the request
trackPass._id = req.params.id;
trackPass.save(function (err) { ... }
I get the following error:
{ [CastError: Cast to ObjectId failed for value "b205ac4d-fd96-4b1e-892a-d4fab818ea2a" at path "vehicle"]
message: 'Cast to ObjectId failed for value "b205ac4d-fd96-4b1e-892a-d4fab818ea2a" at path "vehicle"',
name: 'CastError',
type: 'ObjectId',
value: ["b205ac4d-fd96-4b1e-892a-d4fab818ea2a"],
path: 'vehicle' }
I believe this error makes sense as I'm now using Strings which are longer than typical Mongo ObjectIDs. Without having the ObjectID reference, I don't believe I will be able to populate() referenced objects from other collections. I suppose I could simply not reference the other nested objects in my schema definitions, however I don't like this approach as I feel I will be losing a lot of the benefit of utilizing the ODM. Any other thoughts?
You can still use populate() with _id values of types besides ObjectID, but you do need to use the same type in the reference definition.
So your trackPassSchema would need to change to:
var trackPassSchema = new Schema({
_id: { type: String, default: function genUUID() {
return uuid.v1()
}},
vehicle: [
{type: String, required: true, ref: 'Vehicle'}
]
});
As Adam notes in the comments, you could simplify your default value to:
var trackPassSchema = new Schema({
_id: { type: String, default: uuid.v1 },
vehicle: [
{type: String, required: true, ref: 'Vehicle'}
]
});
Both JohnnyHK and Adam C answers are correct. But if you're using uuid in schema for an array of objects, it is good to use it like this
var trackPassSchema = new Schema({
_id: { type: String, default: () => uuid.v1 },
vehicle: [
{type: String, required: true, ref: 'Vehicle'}
]
});
Because, in one such scenario when i tried using like this _id: { type: String, default: () => uuid.v1 } multiple objects of the array had the same id.
It is not possible in this case as _id is unique field, but it can happen when you are using with fields that aren't unique.
I have my model:
var QuestionSchema = new Schema({
title: String,
question: String,
answers: [String],
set_id: String
});
And I update like so:
questionModel.update({
_id: id
}, {
$set: {
title: req.body.title,
question: req.body.question,
answers: req.body.answers
}
}, function (err, numAffected) {
});
I've checked req.body.answers and it is an array, however, it seems to get saved in the DB as foo,bar, as in, a string, not an array!
Any ideas?
answers: req.body.answers[0]
Was the eventual workaround, no idea why!? If anyone can shed any light on why it was coming from a form with inputs: name="answers[]" being passed as [[foo, bar]]...
I suspect that because you've used '[String]' instead of 'Array' in your schema definition, then when you go to update the model, the array is cast to a string, rather than being saved as an array. Try the below:
var QuestionSchema = new Schema({
title: String,
question: String,
answers: Array,
set_id: String
});
It also looks like you would only use brackets around a schema type where you are defining meta properties:
var animalSchema = new Schema({
name: String,
type: String,
tags: { type: [String], index: true } // field level
});