I'm using Monk to connect to to MongoDB from NodeJS.
I am trying to pull an item from an array, and for that purpose I'm using
db.collection('MYCOLLECTION').update({_id:id},{$pull:{reviews:{userId:userId}}, function(err,data){
console.log(data);
})
When I execute this sentence directly in Mongo (through the console), the function returns an object with three properties:
nMatched
nUpserted
nModified
However, when I do the same thing using monk, I am only getting a value '1' which I supposed is the value of the property nMatched. Is there a way for me to get the nModified property?
Related
Im not able to fetch the field value i need only the value of the particular field in node js query, but coming undefined
I need the nodejs query of this mongodb query
Try using projection into find query to return only values you want.
Also don't forget to use await or get the field name into then. And, of course, the query should return any document to get the field.
Check this example which would be similar in Node:
const value = await db.collectionsname.findOne({mobilenumber: mobilenumber},{_id: 0, field: 1}).fieldname
Projection stage is not mandatory but if you only want that value is a good practice not get all document from the DB.
I'm currently trying to return the document I just added to a collection to display it in real time on my homepage.
I followed a solution I found here: link to 2018 solution. But this solution doesn't seem to work for the latest node.js and MongoDb versions.
I'm essentially trying to do the same thing the person in that post was trying to do but I get the following error:
res.json (info.ops[0]);
TypeError: Cannot read property '0' of undefined
Here's my code for reference:
app.post('create-item', (req, res) => {
dB.collection('items').insertOne({text: req.body.text}, (err, info) => {
res.json(info.ops[0]);});});
When we use insertOne with the Nodejs driver 4 (the latest) we get a response like
{"acknowledged" : true, "insertedId" : #object[ObjectId 61105622b633ecabf3706782]}
Save the document to a variable before inserting it.
If the document had _id, check if it was inserted and get the document from the variable.
If the document didn't had _id, check if it was inserted and get the _id also from the response, and add that _id to the document you have in the variable.
Maybe i am missing something but the above is simple to do, if this is what you need.
First time working with MongoDB. This query works for me in cmd line:
db.secrets.update({_id: ObjectId("5f767cd481cea1687b3dbf86")}, {$set: {secret_rating: 5}})
However, updating a record using essentially the same query on my node server is not completing this task when pinged. Am I wrong in trying to query for a record like so in my model? ObjectId obviously isn't native to my server.
db.secrets.update({_id: "5f767cd481cea1687b3dbf86"}, {$set: {secret_rating: 5}})
Assuming you're using the Nodejs Mongodb driver and not some ORM (since it hasn't been specified), two points of concern:
As far as my knowledge serves, if you have a connection object to your desired database in the db variable, you cannot reference collections directly such as you've done with db.secrets; you must instead use the collection method like so:
const secrets = db.collection("secrets");
secrets.find({
/*your query here*/
}).then((results) => {})
So, unless you've assigned db.secrets with db.collection("secrets") you should be getting an error, Cannot read property "update" of undefined. But I'm going to assume you've got the collection object in db.secrets since you did not mention you're getting that error.
You seem to be using a string instead of an ObjectID object. You can import the ObjectID constructor from the nodejs driver like so:
const ObjectID = require('mongodb').ObjectID
Then in your query, you will have to make a new ObjectID to get the correct result:
db.collection("secrets").find({
_id: new ObjectID("5f767cd481cea1687b3dbf86")
}).then((results) => {})
NOTE: The ObjectID constructor will throw an error if the string supplied to it is not a valid, 24-char hex string, so, if you're getting the id string as an input from somewhere (say, as a parameter in an API or as a command line argument), you might want to wrap it in a function that handles that error.
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
I had a very weird issue with the way Mongoose interacted with my Node and Mongo database.
I was using express to create a basic get api route to fetch some data from my mongodb.
I had a database called test and it had a collection call "billings"
so the schema and route was pretty basic
apiRouter.route('/billing/')
.get(function(req, res) {
Billing.find(function(err, billings) {
if (err) res.send(err);
// return the bills
res.json(billings);
});
});
Where "Billing" was my mongoose schema. that simply had 1 object {test: string}
This worked fine, I got a response with all the items in my mongo db called "billings" which is only one item {test: "success"}
Next I created a collection called "historys"
I setup the exact same setup as my billings.
apiRouter.route('/historys/')
// get all the history
.get(function(req, res) {
Historys.find(function(err, historys) {
if (err) res.send(err);
// return the history
res.json(historys);
});
});
where again "Historys" was my mongoose schema. This schema was identical in setup to my billings since I didnt have any real data, the fields were the same, i just had it with a test field so the json object returned from both billings and historys should have been
{ test: "success" }
However, this time I didnt get any data back, I just got an empty object
[].
I went through my code multiple times to make sure maybe a capital got lost, or a comma somewhere etc, but the code was identical. the setup and formatting in my mongodb was identical. I went into robomongo and viewed the database and everything was named correctly.
Except, I had 2 new collections now.
My original : "Historys" AND a brand new collection "Histories"
Once i fixed my api route to go look at Histories instead of Historys, I was able to get the test data successfully. I still however cannot pull data from Historys, its like it doesnt exist yet there it was in my robomongo console when I refreshed.
I searched all my code for any mention of histories and got 0 results. Where did the system know to fix the grammar on my collection?
From the docs:
When no collection argument is passed, Mongoose produces a collection name by passing the model name to the utils.toCollectionName method. This method pluralizes the name. If you don't like this behavior, either pass a collection name or set your schemas collection name option.
So, when you did, in your schema definition, this:
mongoose.model('Historys', YourSchema);
, mongoose created the Histories collection.
When you do:
db.historys.insert({ test: "success" })
through mongodb console, if the historys collection doesn't exist, it'll be created. That's why you have the two collections in your db. Like the docs said, if you don't want mongoose to create a collection with a pluralized name based on your model, just specify the name you want.