This can be easily achieved using MongoDB update(). Let us create a collection with documents −
> db.demo162.insertOne({"StudentName":"Chris"}); { "acknowledged" : true, "insertedId" : ObjectId("5e3684359e4f06af551997c2") } > db.demo162.insertOne({"StudentName":"Bob"}); { "acknowledged" : true, "insertedId" : ObjectId("5e3684389e4f06af551997c3") } > db.demo162.insertOne({"StudentName":"David"}); { "acknowledged" : true, "insertedId" : ObjectId("5e36843c9e4f06af551997c4") }
Display all documents from a collection with the help of find() method −
> db.demo162.find();
This will produce the following output −
{ "_id" : ObjectId("5e3684359e4f06af551997c2"), "StudentName" : "Chris", "StudentAge" : 23 } { "_id" : ObjectId("5e3684389e4f06af551997c3"), "StudentName" : "Bob" } { "_id" : ObjectId("5e36843c9e4f06af551997c4"), "StudentName" : "David" }
Here is the query to update a document, adding new keys in first document −
> db.demo162.update({},{$set:{"StudentAge":23}},{upsert:true}); WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
Display all documents from a collection with the help of find() method −
> db.demo162.find();
This will produce the following output −
{ "_id" : ObjectId("5e3684359e4f06af551997c2"), "StudentName" : "Chris", "StudentAge" : 23 } { "_id" : ObjectId("5e3684389e4f06af551997c3"), "StudentName" : "Bob" } { "_id" : ObjectId("5e36843c9e4f06af551997c4"), "StudentName" : "David" }