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mongodbcollectionsfindposition

Get position of selected document in collection [mongoDB]

How to get position (index) of selected document in mongo collection?

E.g. this document: db.myCollection.find({"id":12345}) has index 3 in myCollection

myCollection:
    id: 12340, name: 'G'
    id: 12343, name: 'V'
    id: 12345, name: 'A'
    id: 12348, name: 'N'
Solution

  • If your requirement is to find the position of the document irrespective of any order, that is not possible as MongoDb does not store the documents in specific order. However,if you want to know the index based on some field, say _id , you can use this method.

    If you are strictly following auto increments in your _id field. You can count all the documents that have value less than that _id, say n , then n + 1 would be index of the document based on _id.

    n = db.myCollection.find({"id": { "$lt" : 12345}}).count() ;

    This would also be valid if documents are deleted from the collection.