How to increment a field in MongoDB?

To increment a field in MongoDB, you can use $inc operator. Let us first create a collection with documents −

> db.incrementDemo.insertOne({"PlayerScore":100});
{
   "acknowledged" : true,
   "insertedId" : ObjectId("5cc81cdd8f9e6ff3eb0ce44e")
}
> db.incrementDemo.insertOne({"PlayerScore":290});
{
   "acknowledged" : true,
   "insertedId" : ObjectId("5cc81ce28f9e6ff3eb0ce44f")
}
> db.incrementDemo.insertOne({"PlayerScore":560});
{
   "acknowledged" : true,
   "insertedId" : ObjectId("5cc81ce68f9e6ff3eb0ce450")
}

Following is the query to display all documents from a collection with the help of find() method −

> db.incrementDemo.find().pretty();

This will produce the following output −

{ "_id" : ObjectId("5cc81cdd8f9e6ff3eb0ce44e"), "PlayerScore" : 100 }
{ "_id" : ObjectId("5cc81ce28f9e6ff3eb0ce44f"), "PlayerScore" : 290 }
{ "_id" : ObjectId("5cc81ce68f9e6ff3eb0ce450"), "PlayerScore" : 560 }

Following is the query to increment a field in MongoDB −

> db.incrementDemo.update({ _id:ObjectId("5cc81ce28f9e6ff3eb0ce44f") },{ $inc: {"PlayerScore":10 }});
WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })

In the above query, I have incremented the value 290 with value 10 −

> db.incrementDemo.find().pretty();

This will produce the following output −

{ "_id" : ObjectId("5cc81cdd8f9e6ff3eb0ce44e"), "PlayerScore" : 100 }
{ "_id" : ObjectId("5cc81ce28f9e6ff3eb0ce44f"), "PlayerScore" : 300 }
{ "_id" : ObjectId("5cc81ce68f9e6ff3eb0ce450"), "PlayerScore" : 560 }

Smita Kapse

Published on 21-May-2019 12:29:45

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