To update, just save new ID and remove the old one using remove(). Let us first create a collection with documents −
> db.updatingDemo.insertOne({"StudentName":"Robert"}); { "acknowledged" : true, "insertedId" : ObjectId("5e04dae5150ee0e76c06a04b") } > db.updatingDemo.insertOne({"StudentName":"Bob"}); { "acknowledged" : true, "insertedId" : ObjectId("5e04dae7150ee0e76c06a04c") }
Following is the query to display all documents from a collection with the help of find() method −
> db.updatingDemo.find();
This will produce the following output −
{ "_id" : ObjectId("5e04dae5150ee0e76c06a04b"), "StudentName" : "Robert" } { "_id" : ObjectId("5e04dae7150ee0e76c06a04c"), "StudentName" : "Bob" }
Here is the query to update _id in MongoDB −
> myDocument = db.updatingDemo.findOne({"StudentName":"Bob"}); { "_id" : ObjectId("5e04dae7150ee0e76c06a04c"), "StudentName" : "Bob" } > myDocument._id = 1001; 1001 > db.updatingDemo.insert(myDocument); WriteResult({ "nInserted" : 1 }) > db.updatingDemo.remove({_id:ObjectId("5e04dae7150ee0e76c06a04c")}); WriteResult({ "nRemoved" : 1 })
Following is the query to display all documents from a collection with the help of find() method −
> db.updatingDemo.find();
This will produce the following output −
{ "_id" : ObjectId("5e04dae5150ee0e76c06a04b"), "StudentName" : "Robert" } { "_id" : 1001, "StudentName" : "Bob" }