Is there a way to tell the native MongoDB driver for NodeJS to automatically convert the contents of an _id field into an ObjectID?
Say, in this situation:
db.collection("collection").updateOne({_id: data._id}, data)
It's not that data._id = ObjectID(data.id) is hard, but it's another thing to miss each and every time.
There is no way to do that natively. You can make some function for wrapping your mongo queries where you will check params and if it's "_id" parse it to ObjectId.
Related
I am trying to query an old mongoDB collection in node.js with the native driver.
It uses Legacy UUID as its _id field.
In my code I am using Binary values such as: "2u0kLwUZuEWQvjqOjgQU4g=="
and I want to query the collection with find() operation.
When trying to test it directly with mongoDB I am able to use the following query:
db.getCollection('myCollection').find({_id: BinData(3, "2u0kLwUZuEWQvjqOjgQU4g==")})
to find my item.
But what I need to do is to find multiple items.
So I need to use something like this:
db.getCollection('myCollection').find({_ids: { $in: [BinData(3, "2u0kLwUZuEWQvjqOjgQU4g=="), BinData(3, "3u0kLwUZuEWQvjqOjgQU4g==")...]}})
but it does not seem to work and always returns zero records.
I am not sure why? and what might be the correct way to query multiple Legacy UUIDs?
While using Meteor, I sometimes access the underlying Node Mongo driver so I can make bulk updates and inserts.
const bulk = Coll.rawCollection().initializeOrderedBulkOp();
bulk.insert({key_id: Mongo.Collection.ObjectID()}); // note key_id is an ObjectID
...
bulk.execute();
But the value of the key_id fields ends up being the plain subdocument {_str: '...'} when I look in the database after the insert.
Is there any way to use bulk operations in Node's Mongo library (whatever it is Meteor uses) and keep ObjectID's as Mongo's ObjectID type?
(There's many posts about the nature of the different ID types, and explaining Minimongo, etc. I'm interested specifically about the bulk operations converting ObjectID's into plain objects, and solving that issue.)
From Neil's top-level comment
On a native method you would actually need to grab the native implementation. You should be able to access from the loaded driver through MongoInternals [...]
Mongo.Collection.ObjectID is not a plain ObjectId representation, and is actually a complex object for Meteor internal use. Hence why the native methods don't know how to use the value.
So if you have some field which is an ObjectId, and you're using some method of a Meteor Collection's rawCollection (for example,
.distinct
.aggregate
.initializeOrderedBulkOp
.initializeUnorderedBulkOp
), you'll want to convert your ObjectId's using
const convertedID = new MongoInternals.NpmModule.ObjectID(
originalID._str
);
// then use in one of the arguments to your function or something
const query = {_id: convertedID};
before calling the method on them.
I'm using Node.js + mongodb. I have few documents in my collection and i want to know does my collection have any document matched my condition. Of course i can simply use
myModel.find({ myField: someValue }) and check is anything comes or not. But i want to use solution like sql provides exists keyword? Help me, please
Edit: my bad. I forget to tell that "performance first".
MongoDB's $exists actually doesn't help you very much to find out if a certain document exists in your collection. It is used for example to give you all documents that have a specific field set.
MongoDB has no native support for an sql like exists. What you can use, however, is myModel.findOne({ myField: someValue }) and then check if it is null.
To enhance performance you can tell MongoDB to only load the object id via projection, like this:
myModel.findOne({ myField: someValue }, {_id: 1})
There is an exist mechanism in mongodb, I'll demonstrate a sample below.
For example below, I'm looking for records that have tomato.consensus fields and that it's empty, so I can delete them or avoid them. In case I was looking for "tomato.consensus": Dublin, I'd change Null to Dublin, to match that.
I hope this is helpful, if not fire away any questions
tomato
----consensus
db.movieDetails.updateMany({$and: [
{"tomato.consensus": {$exists: true} },
{"tomato.consensus": null} ] },
]})
I come from MySQL world so mongo queries are a bit difficult to make considering I can't really make sense of mongo style queries. I am trying to make a query for finding a string. The problem is from my very primitive knowledge about mongodb queries, the query I made isn't working. I tried it in mongoose as well in mongo shell.
Schema:
mongoose.Schema({
doctorID : String,
patientIDList : Array // array of strings
});
Query Objective:
I want to find a doctor with doctorID and then look inside the patientIDList for an ID xxx. If the patientIDList doesn't contains xxx then add xxx in the list otherwise just add nothing.
Query:
The 2 queries I tried
MyModel.findOne({'doctorID':newAppointment.doctorID}, {'patientIDList' : newAppointment.patientID}, function(err){...});
MyModel.findOne({'doctorID': newAppointment.doctorID, 'patientIDList': newAppointment.patientID}, function(err){...});
What am I doing wrong? How can I make a query?
It's always a bit of challenge to switch from a SQL to NoSQL DB and other way around. What you are trying to do is check if a value exists in an array. If the array is a string array you can simply query for the value in array.
MyModel.findOne({doctorID : newAppointment.doctorID}, {patientIDList :newAppointment.doctorID}, function(err, res){
console.log(err, res);
})
Further read: https://docs.mongodb.com/manual/tutorial/query-documents/#match-an-array-element
Relevant Question: Find document with array that contains a specific value
Each time I have to perform a query involving _id, I have to do new ObjectID( _idAsString) in order for it to work. I realize mongo tests the object, not the value itself, but this is adding a lot of overhead and I may miss converting it in some places.
The _id goes to the client where the ObjectID( string ) is turned to string and when it comes back from the client, I would have to remake it into ObjectID( string ). I will mention that "string" is the actual value generated by mongo, something like 123a1b12dc...
If there is another good/complete library with such a internal functionality, I would love to try it out.
There are some Node.js object mappers which provide this functionality. Take a look at Mongolia.
https://github.com/masylum/mongolia#mappings-and-type-casting