MongoDB MongoDB CRUD Operations

Question 1

Which method is used to insert a single document into a MongoDB collection?

Accepted Answer

insertOne()

Answer

insertMany()

Answer

save()

Answer

addDocument()

Question 2

What does the findOne() method return when no matching document is found?

Accepted Answer

null

Answer

An empty object {}

Answer

undefined

Answer

An empty array []

Question 3

Which update operator sets the value of a field in a document?

Accepted Answer

$set

Answer

$push

Answer

$inc

Answer

$unset

Question 4

What option must be passed to updateOne() to create a new document if no match is found?

Accepted Answer

{ upsert: true }

Answer

{ createNew: true }

Answer

{ insert: true }

Answer

{ merge: true }

Question 5

Which method removes a single document that matches the filter from a collection?

Accepted Answer

deleteOne()

Answer

removeOne()

Answer

deleteFirst()

Answer

dropOne()

Question 6

What does the $inc operator do in an update operation?

Accepted Answer

Increments or decrements a numeric field by a specified amount

Answer

Inserts a new field

Answer

Indexes a field

Answer

Includes a field in projection