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Questions - aggregation-framework

Updating a nested array using $indexOfArray and $slice in MongoDB

Using the following documents, we are able to do what we need to do which is essentially "re-parenting" a document that stores an array of ancestors like so: db.getCollection("myarrays&...
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Tom

mongodb

mongodb-query

aggregation-framework

Votes: 0

Answers: 1

Latest Answer

You can first $unwind references for easier processing and reusing your working logic. Use $cond to conditionally perform your working logic on elements with parent2. Finally, $group to regroup the un...
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ray

How to get a count of records in MongoDB using a Lookup as a Reference

I'm trying to build a polling system. I have a collection of choices and a collection of votes Choices collection, showing the choices available in 'poll1' _id:'1', pollId:'poll1', choice:'red' _id:'...
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Ray Purchase

mongodb

aggregation-framework

Votes: 0

Answers: 1

Latest Answer

You can use this aggregation query: First $match by your poll name (as you do). Then use $lookup to merge collections. But here there are a few thing to do better: from is the other collection, local...
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J.F.

Mongo Group By query

I have data stored in a Mongo collection that is structured like this: { "numberAtPending" : 3, "numberAtInProgress" : 5, "numberAtCancelled" : 1, "...
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R111

sql

mongodb

mongodb-query

aggregation-framework

grouping

Votes: 0

Answers: 1

Latest Answer

You can try this query (also I'm assuming the output you show is an example and not the real values because I don't know from where can you get 300, 150, 400...) So, try this: You have two options to ...
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J.F.

Query documents with parent and child in same collection MongoDB

So, i have a mongoDB collection with the following documents: [ { "_id": { "$oid": "61e928d2f6b1431588765bd4" }, "uniqueID": 1, "pa...
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Sahil Doshi

mongodb

mongodb-query

aggregation-framework

Votes: 0

Answers: 1

Latest Answer

try this for getting the the child having max(uniqueId) for a given parent db.getCollection('your_collection_name').aggregate([ {$sort: {"uniqueID" : 1}}, {$group: { _id: "$par...
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indybee

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