Nodejs mongoose: how can I find a subset of all documents? - node.js

I have a collection in mongodb that has more than 100000 documents. Each time I apply Model.find(), it returns all documents in an array.
But for some reasons like unnecessary data or performance, speed of the query, I just want to find document that is:
Starting with first document
The second document will be the 300th document
The third document will be the 600th document
...
The final document will be the 100000th document
Is there any mongoose query for that?

Related

What can be an alternative to mongoose populate in native mongodb driver where my query may return multiple documents

What can be an alternative to mongoose populate for mongodb driver where my query may return multiple documents and each document can have multiple children(max 5-6) stored in different collection. I want each document populated with children props.
fx.
a user has multiple orders and each order has many items(each order only stores the id of an item). Now I've a query to get orders between specific time period and that will reurn multiple orders and now i want these orders to be populated with item(fx item price, item size)
one potential solution could be get all orders and make 5-6(no. of items) additional query, which i assume to be a performance bottleneck
*Nodejs mongo driver

Is there any way to find distinct documents in mongo using nodejs

I actually want To display Full documents Without duplication
When I use distinct i can only display one particular field
How to display all fields without selecting that document which is repeated
Each document in MongoDB contains an _id field which must be unique in the collection. Hence, it is not possible to have two identical documents in a collection. Ergo, iterating a collection with no conditions will return all unique documents (which are all documents in the collection).

How can I fetch the most recently added document using mongoose?

I am trying to fetch the most recent document in MongoDB using mongoose.
Every method I have tried so far gives me the oldest document on record.
I've tried sorting by date, and created_at
Tried both ascending and descending, both return the oldest document.
https://paste.heckyou.ml/odofomasel.js
The value returned should be the most recently added document.
This will give you one last document for a collection
db.collectionName.findOne({}, {sort:{$natural:-1}})
$natural:-1 means order opposite of the one that records are inserted in.
mongo CLI syntax is: db.collectionName.find({}).sort({$natural:-1}).limit(1)

Deleting mongodb subdocument on certain date

I have a collection which stores document that can have multiple subdocument (e.g. a group collection with multiple votings). My goal is to delete certain subdocuments on a certain date. I thought about using a package like "agenda" to cron-like delete certain subdocuments. Are there any more efficient or easier ways to do that

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i need to develop a search application , where many documents are indexed with different fields and a id field which is unique for each of the document . Fields are not stored just indexed except for id field
i need to find out for each document , the documents similar to this, here all i have is unique id field of current document , i dont have any other fields of current document to form Terms and query the index for finding similar documents like current one.
How do i do this ? any help greatly appreciated .
I believe the simplest way to do this is to use Solr, and use Solr's MoreLikeThisHandler.
You can use a query likehttp://localhost:8983/solr/select?q=unique_id:2722&mlt=true&mlt.fl=manu,cat&mlt.mindf=1&mlt.mintf=1&fl=id,score
Do you have any control over how these documents are indexed? You can index with term vectors, and at query time, look up the term vector for the document, construct a query using the terms, and submit the query.

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