How to update only one property in MongoDB?

To update only one property, use $addToSet in MongoDB. Let us create a collection with documents −

> db.demo336.insertOne({"Name":"Chris","Score":[45,67,78]});
{
   "acknowledged" : true,
   "insertedId" : ObjectId("5e522cb1f8647eb59e562097")
}
> db.demo336.insertOne({"Name":"David","Score":[89,93,47]});
{
   "acknowledged" : true,
   "insertedId" : ObjectId("5e522cb2f8647eb59e562098")
}

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

> db.demo336.find();

This will produce the following output −

{ "_id" : ObjectId("5e522cb1f8647eb59e562097"), "Name" : "Chris", "Score" : [ 45, 67, 78 ] }
{ "_id" : ObjectId("5e522cb2f8647eb59e562098"), "Name" : "David", "Score" : [ 89, 93, 47 ] }

Following is the query to update only one property in MongoDB −

> db.demo336.update({Name:"David"},{ $addToSet: {Score: [56,34,71] }});
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })

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

> db.demo336.find();

This will produce the following output −

{ "_id" : ObjectId("5e522cb1f8647eb59e562097"), "Name" : "Chris", "Score" : [ 45, 67, 78 ] }
{ "_id" : ObjectId("5e522cb2f8647eb59e562098"), "Name" : "David", "Score" : [ 89, 93, 47, [ 56, 34, 71 ] ] }