How to stop insertion of Duplicate documents in a mongodb collection

Question

Let us have a MongoDB collection which has three docs..

db.collection.find()

 { _id:\'...\', user: \'A\', title: \'Physics\',   Bank: \'         


        

Answer 1

It has been updated from the above answers.

please use db.collection.updateOne() instead of db.collection.update(). and also db.collection.createIndexes() instead of db.collection.ensureIndex()

Update: the methods update() and ensureIndex() has been deprecated from mongodb 2.*, you can see more details in mongo and the path is ./mongodb/lib/collection.js. For update(), the recommend methods are updateOne, updateMany, or bulkWrite. For ensureIndex(), the recommend method is createIndexes.