MongoDB query to update only a single item from voting (up and down) records?

Let us first create a collection with documents −

> db.demo57.insertOne({"Votes":{"VoterName":"Chris","TotalVote":50}}); {    "acknowledged" : true,    "insertedId" : ObjectId("5e285bb8cfb11e5c34d8991a") } > db.demo57.insertOne({"Votes":{"VoterName":"David","TotalVote":101}}); {    "acknowledged" : true,    "insertedId" : ObjectId("5e285bc3cfb11e5c34d8991b") }

Display all documents from a collection with the help of find() method −

> db.demo57.find();

This will produce the following output −

{ "_id" : ObjectId("5e285bb8cfb11e5c34d8991a"), "Votes" : { "VoterName" : "Chris", "TotalVote" : 50 } } { "_id" : ObjectId("5e285bc3cfb11e5c34d8991b"), "Votes" : { "VoterName" : "David", "TotalVote" : 101 } }

Here is the query to update only a single item (TotalVote) −

> db.demo57.update({"Votes.VoterName":"David" },{ $inc : { "Votes.TotalVote" : 19 } }); WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })

Display all documents from a collection with the help of find() method −

> db.demo57.find();

This will produce the following output −

{ "_id" : ObjectId("5e285bb8cfb11e5c34d8991a"), "Votes" : { "VoterName" : "Chris", "TotalVote" : 50 } } { "_id" : ObjectId("5e285bc3cfb11e5c34d8991b"), "Votes" : { "VoterName" : "David", "TotalVote" : 120 } }