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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 } }
Updated on: 03-Apr-2020
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