Why modeling decisions matter in MongoDB - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to find all documents in the collection.

MongoDB

db.collection.[1]()

Drag options to blanks, or click blank then click option'

Afind

Binsert

Cupdate

Ddelete

Attempts:

3 left

💡 Hint

Common Mistakes

Using insert instead of find will add data, not retrieve it.

Using update or delete will modify or remove data, not retrieve.

The find() method retrieves all documents from a MongoDB collection.

2fill in blank

medium

Complete the code to insert a new document into the collection.

MongoDB

db.collection.[1]({ name: 'Alice', age: 30 })

Drag options to blanks, or click blank then click option'

AdeleteOne

Bfind

CinsertOne

DupdateOne

Attempts:

3 left

💡 Hint

Common Mistakes

Using find will not add data.

Using deleteOne or updateOne will remove or change data, not add.

The insertOne() method adds a single new document to the collection.

3fill in blank

hard

Fix the error in the query to update a document's age.

MongoDB

db.collection.updateOne({ name: 'Bob' }, { [1]: { age: 35 } })

Drag options to blanks, or click blank then click option'

Aupdate

Bset

C$update

D$set

Attempts:

3 left

💡 Hint

Common Mistakes

Missing the dollar sign causes the update to fail.

Using 'set' without $ is not recognized by MongoDB.

The $set operator updates specific fields in a document.

4fill in blank

hard

Fill both blanks to create a query that finds documents where age is greater than 25.

MongoDB

db.collection.find({ age: { [1]: [2] } })

Drag options to blanks, or click blank then click option'

A$gt

B25

C$lt

D30

Attempts:

3 left

💡 Hint

Common Mistakes

Using $lt finds ages less than the number, not greater.

Using 30 instead of 25 changes the filter condition.

The $gt operator means 'greater than'. So this finds documents with age > 25.

5fill in blank

hard

Fill all three blanks to create a query that finds documents with name 'Eve' and age less than 40.

MongoDB

db.collection.find({ name: [1], age: { [2]: [3] } })

Drag options to blanks, or click blank then click option'

A'Eve'

B$lt

C40

D'Alice'

Attempts:

3 left

💡 Hint

Common Mistakes

Using wrong name string changes the filter.

Using $gt instead of $lt reverses the age condition.

This query finds documents where name is 'Eve' and age is less than 40 using $lt.