Collections vs tables mental model in MongoDB - Interactive Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to find all documents in the collection.

MongoDB

db.users.[1]()

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

Afind

Bdelete

Cupdate

Dinsert

Attempts:

3 left

💡 Hint

Common Mistakes

Using insert() instead of find() to get data.

Trying to update or delete when just reading.

The find() method retrieves all documents from a MongoDB collection, similar to selecting all rows from a table in SQL.

2fill in blank

medium

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

MongoDB

db.products.[1]({ name: 'Pen', price: 1.5 })

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

Afind

BdeleteOne

CupdateOne

DinsertOne

Attempts:

3 left

💡 Hint

Common Mistakes

Using find() instead of insertOne() to add data.

Using deleteOne() or updateOne() by mistake.

The insertOne() method adds a single new document to a collection, similar to inserting a new row in a table.

3fill in blank

hard

Fix the error in the code to update a document's price.

MongoDB

db.items.updateOne({ name: 'Book' }, { [1]: { price: 12 } })

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

A$add

B$get

C$set

D$remove

Attempts:

3 left

💡 Hint

Common Mistakes

Using $get or $add instead of $set.

Forgetting the dollar sign in the operator.

The $set operator updates the value of a field in a document. Other operators like $get or $add are not valid for updates.

4fill in blank

hard

Fill both blanks to delete all documents where age is less than 18.

MongoDB

db.students.deleteMany({ age: { [1]: [2] } })

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

A$lt

B$gt

C18

D21

Attempts:

3 left

💡 Hint

Common Mistakes

Using $gt (greater than) instead of $lt.

Using wrong age number.

The $lt operator means 'less than'. So this query deletes documents where age is less than 18.

5fill in blank

hard

Fill all three blanks to find documents where status is 'active' and sort by score descending.

MongoDB

db.players.find({ status: [1] }).sort({ [2]: [3] })

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

A'active'

Bscore

C-1

D1

Attempts:

3 left

💡 Hint

Common Mistakes

Forgetting quotes around 'active'.

Using 1 instead of -1 for descending sort.

The query finds documents with status 'active' and sorts them by score in descending order using -1.