I’m looking for the fastest way to get all objectIDs of a collection with a privacy value 'public'.
In this image, privacy's value is 'public', so node should give me the '_id' of this object (in this example '57bc4b9f466fab7c099a3f94').
My attempt:
var mongoose = require('mongoose');
mongoose.connect('localhost:27017/databasename');
var Schema = mongoose.Schema;
var collectionsNameSchema = new Schema({
updated: {type: Date },
privacy: { type: Object }
}, {collection: 'spots'});
var collectionsNameData = mongoose.model('collectionsNameData', collectionsNameSchema);
...
collectionsNameData.find({privacy: 'public'})
From what i see you have a problem in query to mongoDB.
Try like this.
collectionsNameData.find({'privacy.value': 'public'});
This should return desired result.
You also may want to use projection as second parameter in find to return only fields that you want. Keep in mind that _id returned by default.
Hope this helps.
Using Mongoose, how do I access a subdocument in an array? In the schema I have declared my subdocument using an object-literal as per the docs.
After I have retrieved the parent document I can log out doc.children and see the array of objects, but when I attempt to access any of the documents I get undefined. doc.children is not returned as an array, so how do I access the subdocuments?
Schema:
var parentSchema = new Schema({
children: [{ name: 'string' }]
});
Usage:
console.log(doc.children); //[{name: 'hello'}, {name: 'world'}]
doc.children[0]; //undefined
doc.children['0']; //undefined
The code above looks almost exactly like the documentation here:
http://mongoosejs.com/docs/subdocs.html
I am thinking perhaps there is something else in your code acting strange that you've not displayed here. Perhaps try using get: http://mongoosejs.com/docs/api.html#document_Document-get
doc.get('children')
i have a model schema as :
var A = new Schema ({
a: String,
b : [ { ba: Integer, bb: String } ]
}, { collection: 'a' } );
then
var M = mongoose.model("a", A);
var saveid = null;
var m = new M({a:"Hello"});
m.save(function(err,model){
saveid = model.id;
}); // say m get the id as "1"
then
m['b'].push({ba:235,bb:"World"});
m.save(function(err,model){
console.log(model.id); //this will print 1, that is the id of the main Document only.
//here i want to find the id of the subdocument i have just created by push
});
So my question is how to find the id of the subdocument just pushed in one field of the model.
I've been looking for this answer as well, and I'm not sure that I like accessing the last document of the array. I do have an alternative solution, however. The method m['b'].push will return an integer, 1 or 0 - I'm assuming that is based off the success of the push (in terms of validation). However, in order to get access to the subdocument, and particularly the _id of the subdocument - you should use the create method first, then push.
The code is as follows:
var subdoc = m['b'].create({ ba: 234, bb: "World" });
m['b'].push(subdoc);
console.log(subdoc._id);
m.save(function(err, model) { console.log(arguments); });
What is happening is that when you pass in the object to either the push or the create method, the Schema cast occurs immediately (including things like validation and type casting) - this means that this is the time that the ObjectId is created; not when the model is saved back to Mongo. In fact, mongo does not automatically assign _id values to subdocuments this is a mongoose feature. Mongoose create is documented here: create docs
You should also note therefore, that even though you have a subdocument _id - it is not yet in Mongo until you save it, so be weary of any DOCRef action that you might take.
The question is "a bit" old, but what I do in this kind of situation is generate the subdocument's id before inserting it.
var subDocument = {
_id: mongoose.Types.ObjectId(),
ba:235,
bb:"World"
};
m['b'].push(subDocument);
m.save(function(err,model){
// I already know the id!
console.log(subDocument._id);
});
This way, even if there are other database operations between the save and the callback, it won't affect the id already created.
Mongoose will automatically create an _id for each new sub document, but - as far as I know - doesn't return this when you save it.
So you need to get it manually. The save method will return the saved document, including the subdocs. As you're using push you know it will be the last item in the array, so you can access it from there.
Something like this should do the trick.
m['b'].push({ba:235,bb:"World"});
m.save(function(err,model){
// model.b is the array of sub documents
console.log(model.b[model.b.length-1].id);
});
If you have a separate schema for your subdocument, then you can create the new subdocument from a model before you push it on to your parent document and it will have an ID:
var bSchema = new mongoose.Schema({
ba: Integer,
bb: String
};
var a = new mongoose.Schema({
a: String,
b : [ bSchema ]
});
var bModel = mongoose.model('b', bSchema);
var subdoc = new bModel({
ba: 5,
bb: "hello"
});
console.log(subdoc._id); // Voila!
Later you can add it to your parent document:
m['b'].push(subdoc)
m.save(...
I am new to node.js, so I have a feeling that this will be something silly that I have overlooked, but I haven't been able to find an answer that fixes my problem. What I'm trying to do is create a path that will create a new child object, add it to the parent's array of children, then return the child object to the requester. The problem that I am running into is that if I pass the string id into findById, node crashes with
TypeError: Object {} has no method 'cast'
If I try to pass in an ObjectId instead, I get
CastError: Cast to ObjectId failed for value "[object Object]" at path "_id"
Here is a rough outline of my code:
var mongoose = require('mongoose');
var Schema = mongoose.Schema;
var ObjectId = Schema.ObjectId; //Have also tried Schema.Types.ObjectId, mongoose.ObjectId
mongoose.connect('mongodb://user:password#server:port/database');
app.get('/myClass/:Id/childClass/create', function(request, result) {
var id = new ObjectId(request.params.Id);
MyClass.findById(id).exec( function(err, myClass) {
if (err || !myClass) { result.send("error: " + err + "<br>" + JSON.stringify(id) || ("object '" + request.params.Id + "' not found: " + id)); return; }
var child = ChildClass();
myClass.Children.addToSet(child);
myClass.save();
result.send(child);
});
});
If I execute this code with the path "/myClass/51c35e5ced18cb901d000001/childClass/create", this is the output of the code:
error: CastError: Cast to ObjectId failed for value "[object Object]" at path "_id"
{"path":"51c35e5ced18cb901d000001","instance":"ObjectID","validators":[],"setters":[],"getters":[],"_index":null}
I've tried using findOne and passing in {_id:id} instead, but this appears to be exactly what findById does. I've tried the different classes for ObjectId that I've seen listed on other sites. I've tried calling ObjectId() like a function instead of a constructor and that returns undefined. At this point, I'm running out of ideas and it doesn't seem that googling for an answer is helping. Any ideas on what I'm doing wrong?
Also, like I said, I'm new to node/Mongo/Mongoose/Express, so if there is a better way to accomplish my goal, please let me know. I appreciate all feedback.
EDIT:
After the workaround from Peter Lyons, I googled another error that I was running into and found findByIdAndUpdate, which works as expected and does exactly what I was hoping to do. I'm still not sure why findById and findOne were giving me such issues and I'm curious to know (maybe a bug report needs to be filed), so I'll leave this open in case someone else has an answer.
Short answer: use mongoose.Types.ObjectId.
Mongoose (but not mongo) can accept object Ids as strings and "cast" them properly for you, so just use:
MyClass.findById(req.params.id)
However, the caveat is if req.params.id is not a valid format for a mongo ID string, that will throw an exception which you must catch.
So the main confusing thing to understand is that mongoose.SchemaTypes has stuff you only use when defining mongoose schemas, and mongoose.Types has the stuff you use when creating data objects you want to store in the database or query objects. So mongoose.Types.ObjectId("51bb793aca2ab77a3200000d") works, will give you an object you can store in the database or use in queries, and will throw an exception if given an invalid ID string.
findOne takes a query object and passes a single model instance to the callback. And findById is literally a wrapper of findOne({_id: id}) (see source code here). Just find takes a query object and passes an array of matching model instances to the callback.
Just go slow. It's confusing but I can guarantee you you are getting confused and not hitting bugs in mongoose at this point. It's a pretty mature library, but it takes some time to get the hang of it.
The other suspect thing I see in your snippet is not using new when instantiating ChildClass. Beyond that, you'll need to post your schema code in order for us to help you tract down any CastErrors that remain.
I've faced this error, That was because the value you want to filter in the _id field is not in an ID format, one "if" should solve your error.
const mongoose = require('mongoose');
console.log(mongoose.Types.ObjectId.isValid('53cb6b9b4f4ddef1ad47f943'));
// true
console.log(mongoose.Types.ObjectId.isValid('whatever'));
// false
To solve it, always validate if the criteria value for search is a valid ObjectId
const criteria = {};
criteria.$or = [];
if(params.q) {
if(mongoose.Types.ObjectId.isValid(params.id)) {
criteria.$or.push({ _id: params.q })
}
criteria.$or.push({ name: { $regex: params.q, $options: 'i' }})
criteria.$or.push({ email: { $regex: params.q, $options: 'i' }})
criteria.$or.push({ password: { $regex: params.q, $options: 'i' }})
}
return UserModule.find(criteria).exec(() => {
// do stuff
})
For all those people stuck with this problem, but still couldn't solve it: I stumbled upon the same error and found the _id field being empty.
I described it here in more detail. Still have not found a solution except changing the fields in _id to not-ID fields which is a dirty hack to me. I'm probably going to file a bug report for mongoose. Any help would be appreciated!
Edit: I updated my thread. I filed a ticket and they confirmed the missing _id problem. It is going to be fixed in the 4.x.x version which has a release candidate available right now. The rc is not recommended for productive use!
If you are having this issue and you are performing a populate somewhere along the lines, see this Mongoose issue.
Update to Mongoose 4.0 and the issue has been fixed.
Had the same problem, I just coerced the id into a string.
My schema:
const product = new mongooseClient.Schema({
retailerID: { type: mongoose.SchemaTypes.ObjectId, required: true, index: true }
});
And then, when inserting:
retailerID: `${retailer._id}`
I had the same problem, turned out after I have updated my schema, I have forgotten I was calling the model using the old id, which was created by me; I have updated my schema from something like:
patientid: {
type: String,
required: true,
unique: true
},
to
patientid: { type: mongoose.SchemaTypes.ObjectId, ref: "Patient" },
It turned out, since my code is big, I was calling the findOne with the old id, therefore, the problem.
I am posting here just to help somebody else: please, check your code for unknown wrong calls! it may be the problem, and it can save your huge headacles!
My solution is that I want data from all docs, and I don't want _id, so
User.find({}, {_id:0, keyToShow:1, keyToNotShow:0})
I was receiving this error CastError: Cast to ObjectId failed for value “[object Object]” at path “_id” after creating a schema, then modifying it and couldn't track it down. I deleted all the documents in the collection and I could add 1 object but not a second. I ended up deleting the collection in Mongo and that worked as Mongoose recreated the collection.
For the record: I had this error trying to fill a subdocument in a wrong way:
{
[CastError: Cast to ObjectId failed for value "[object Object]" at path "_id"]
message: 'Cast to ObjectId failed for value "[object Object]" at path "_id"',
name: 'CastError',
type: 'ObjectId',
path: '_id'
value:
[ { timestamp: '2014-07-03T00:23:45-04:00',
date_start: '2014-07-03T00:23:45-04:00',
date_end: '2014-07-03T00:23:45-04:00',
operation: 'Deactivation' } ],
}
look ^ value is an array containing an object: wrong!
Explanation: I was sending data from php to a node.js API in this way:
$history = json_encode(
array(
array(
'timestamp' => date('c', time()),
'date_start' => date('c', time()),
'date_end' => date('c', time()),
'operation' => 'Deactivation'
)));
As you can see $history is an array containing an array. That's why mongoose try to fill _id (or any other field) with an array instead than a Scheme.ObjectId (or any other data type). The following works:
$history = json_encode(
array(
'timestamp' => date('c', time()),
'date_start' => date('c', time()),
'date_end' => date('c', time()),
'operation' => 'Deactivation'
));
I am not sure this will help but I resolved the issue by importing mongoose like below and implementing it as below
const mongoose = require('mongoose')
_id: new mongoose.Types.ObjectId(),
I also encountered this mongoose error
CastError: Cast to ObjectId failed for value \"583fe2c488cf652d4c6b45d1\" at path \"_id\" for model User
So I run npm list command to verify the mongodb and mongoose version in my local.
Heres the report:
......
......
├── mongodb#2.2.19
├── mongoose#4.7.2
.....
It seems there's an issue on this mongodb version so what I did is I uninstall and try to use different version such as 2.2.16
$ npm uninstall mongodb, it will delete the mongodb from your node_modules directory. After that install the lower version of mongodb.
$ npm install mongodb#2.2.16
Finally, I restart the app and the CastError is gone!!
I was having the same problem.Turns out my Node.js was outdated. After upgrading it's working.
just change the path it will work for example
app.get('/myClass/:Id/childClass/create', function(request, result) .....
change to
app.get('/myClass**es**/:Id/childClass/create', function(request, result) .....
I just added --es-- to the path (myClass) to become (myClasses)
now should work and will not see that error
For me, the ID was undefined (req.params.id returns undefined)
If you're finding a document by its "_id" for a model, say Drivers, the command below works quite well:
....
const driver = await Drivers.findById(<your id>);
....
Ensure you use the async-await and try-catch ES6 syntax
For me, I was using a put request without sending any data. I changed it to a post request and it worked.
This thread covers more about put requests.
just change the path it will work for example
app.get('/myClass/:Id/childClass/create', function(request, result)
change to
app.get('/myClass**es**/:Id/childClass/create', function(request, result)
I just added --es-- to the path (myClass) to become (myClasses)
now should work and will not see that error
here is my code for models.js where I keep models
var mongoose = require('mongoose')
, Schema = mongoose.Schema;
var GroupSchema = new Schema({
title : String
, elements : [ElementSchema]
, author : String
});
var ElementSchema = new Schema({
date_added : Date
, text : String
, author : String
});
mongoose.model('Group', GroupSchema);
exports.Group = function(db) {return db.model('Group');};
mongoose.model('Element', ElementSchema);
exports.Element = function(db) { return db.model('Element');
};
To me it looks pretty clear, but when I do
function post_element(req, res, next) {
Group.findOne({_id: req.body.group}, function(err, group) {
new_element = new Element({author: req.body.author,
date_added: new Date()});
new_element.save();
group.elements.push(new_element);
group.save();
res.send(new_element);
return next();
})
}
I don't understand why when I go in Mongo I have two collections one called Groups with nested groups (so it looks fine) and the other collection is called Elements.
Why? Shouldn't it be called just Group ?
I don't understand, a good chap that please explain it to me?
Thanks,
g
When you execute this line:
new_element.save();
you're saving the newly created element to the Elements collection. Don't call save on the element and I think you'll get the behavior you're looking for.
Its because of the following line:
mongoose.model('Element', ElementSchema);
This registers a model in mongoose and when you register a model, it will create its own collection inside mongo. All you have to do is get rid of this line and you will see it disappear.
On another note, its much cleaner and easier to setup your files to only export one model per file using the following to export the model:
module.exports = mongoose.model('Group', GroupSchema);
Hope this helps!