insertOne method in MongoDB - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does the insertOne method do in MongoDB?

The insertOne method adds a single new document to a MongoDB collection.

beginner

How do you use insertOne to add a document with a name and age?

You call insertOne with an object like { name: 'Alice', age: 30 } to add that document to the collection.

intermediate

What does insertOne return after inserting a document?

It returns a result object containing insertedId, which is the unique ID of the new document.

beginner

Can insertOne insert multiple documents at once?

No, insertOne inserts only one document. To insert many, use insertMany.

intermediate

What happens if you try to insert a document with a duplicate _id using insertOne?

MongoDB will return an error because _id must be unique in a collection.

What is the main purpose of the insertOne method in MongoDB?

A Insert a single document into a collection

B Insert multiple documents into a collection

C Update a document in a collection

D Delete a document from a collection

insertOne adds exactly one new document to a MongoDB collection.

Which of these is a valid argument for insertOne?

A 'name: Bob, age: 25'

B [{ name: 'Bob' }, { age: 25 }]

C { name: 'Bob', age: 25 }

D 42

insertOne expects a single document object, like { name: 'Bob', age: 25 }.

What does insertOne return after a successful insert?

A Nothing

B The number of documents in the collection

C The entire collection

D The inserted document's unique ID

It returns an object containing insertedId, the new document's unique ID.

If you want to add many documents at once, which method should you use instead of insertOne?

A findMany

B insertMany

C deleteMany

D updateMany

insertMany is designed to add multiple documents in one call.

What error occurs if you insert a document with an existing _id using insertOne?

A Duplicate key error

B Syntax error

C Connection error

D No error

MongoDB enforces unique _id values, so duplicates cause a duplicate key error.

Explain how the insertOne method works in MongoDB and what it returns.

Think about adding one item to a list and getting its ID back.

Describe the difference between insertOne and insertMany.

One is for single items, the other for many.