To update selected fields, use UPDATE() in MongoDB. The $set is used to set the new value. Let us create a collection with documents −
> db.demo352.insertOne({"Name":"Chris"}); { "acknowledged" : true, "insertedId" : ObjectId("5e55510af8647eb59e5620ba") } > db.demo352.insertOne({"Name":"David"}); { "acknowledged" : true, "insertedId" : ObjectId("5e55510ef8647eb59e5620bb") } > db.demo352.insertOne({"Name":"Bob"}); { "acknowledged" : true, "insertedId" : ObjectId("5e555112f8647eb59e5620bc") } > db.demo352.insertOne({"Name":"Mike"}); { "acknowledged" : true, "insertedId" : ObjectId("5e555115f8647eb59e5620bd") }
Display all documents from a collection with the help of find() method −
> db.demo352.find();
This will produce the following output −
{ "_id" : ObjectId("5e55510af8647eb59e5620ba"), "Name" : "Chris" } { "_id" : ObjectId("5e55510ef8647eb59e5620bb"), "Name" : "David" } { "_id" : ObjectId("5e555112f8647eb59e5620bc"), "Name" : "Bob" } { "_id" : ObjectId("5e555115f8647eb59e5620bd"), "Name" : "Mike" }
Following is the query to update selected fields only −
> db.demo352.update({Name:"David"},{$set:{"Name":"Robert"}}); WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
Display all documents from a collection with the help of find() method −
> db.demo352.find();
This will produce the following output −
{ "_id" : ObjectId("5e55510af8647eb59e5620ba"), "Name" : "Chris" } { "_id" : ObjectId("5e55510ef8647eb59e5620bb"), "Name" : "Robert" } { "_id" : ObjectId("5e555112f8647eb59e5620bc"), "Name" : "Bob" } { "_id" : ObjectId("5e555115f8647eb59e5620bd"), "Name" : "Mike" }