Category "aggregation-framework"

MongoDB - Loop through array of arrays

I have a document that contains an array of arrays in my MongoDB collection. { "platformId":"CMC_123", "carInfo":[ ["Toyota",20,"White"],

How to create nested array inside $group in MongoDB?

After some of the aggregation pipeline stages, my MongoDB Document has the following format: { "key": "A", "status": "To Do", "val": 4 }, {

lookup on all documents inside an array - MongoDB aggregation

I need to execute a lookup stage on all documents inside an array. The collection: { { "name": "test", "age": 2, "replies": [ {

MongoDB indexes are ignored inside the $facet pipeline

I have all combination of compound indexes for this collection. The aggregattion query i used is: db.products.aggregate( [ { $facet: { "categ

Delete result of mongodb $lookup aggregation

How do I delete all the chunks documents which are returned as a result of this aggregation? db.getCollection('chunks').aggregate([ { $lookup:

MongoDB optimize indexes for aggregation

I have an aggregate on a collection with about 1.6M of registers. That consult is a simple example of other more complex, but illustrate the poor optimization o

MongoDB: subtract months from date, with value from database

Is it possible in MongoDB to somehow subtract only months from a date, with a value from the same document. So for example i have to subtract date from field "v

How do I use Spring Mongo to group two fields and get a array of one fields based on the other?

Let me give a example here: Two entries in the collection Author: { "name" : "Joe" "Book" : "A" }, { "name" : "Joe" "Book" : "B" } Now, if I use the aggrega

MongoDB Duplicate Documents even after adding unique key

I have created a collection and added a unique key like this db.user_services.createIndex({"uid":1 , "sid": 1},{unique:true,dropDups: true}) The collection

Calculate the median in MongoDB aggregation framework

Is there a way to calculate the median using the MongoDB aggregation framework?

group in mongo excluding null values

I have mongo query which does the group operation on the documents. I have almost got the expected results except that I want to refine the results without emp

Performance penalty when using fluent interface

I am an absolute beginner when it comes to MongoDb. Just joined a new project where it is used, so I tried to do few experiments to get myself familiar. I got t

Specify raw aggregate request with Spring Data Mongodb

I write a big aggregate query for mongodb, now I try to translate it in Spring Data Mongodb API, and it's very complicated, and spring data api did not help me

Find duplicate records in MongoDB

How would I find duplicate fields in a mongo collection. I'd like to check if any of the "name" fields are duplicates. { "name" : "ksqn291", "__v" : 0

How to match multiple array elements without using unwind?

I have a collection which contains documents with multiple arrays. These are generally quite large, but for purposes of explaining you can consider the followin

MongoDB Merge Equivalent Collections

I have two collections with same structure and want to merge them in aggregation result and query & sort over them after merging. E.g.; First collection: