Array update with positional $ operator in MongoDB - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to update the first matching element in the array using the positional $ operator.

MongoDB

db.collection.updateOne({ 'items.name': 'apple' }, { $set: { 'items.[1].quantity': 10 } })

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

A$

B0

C1

D*

Attempts:

3 left

💡 Hint

Common Mistakes

Using a numeric index instead of the positional operator.

Using an asterisk or other symbols instead of $.

The positional $ operator updates the first matching element in the array.

2fill in blank

medium

Complete the code to increment the quantity of the matched array element by 5 using the positional $ operator.

MongoDB

db.collection.updateOne({ 'items.name': 'banana' }, { $inc: { 'items.[1].quantity': 5 } })

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

A1

B0

C$

D#

Attempts:

3 left

💡 Hint

Common Mistakes

Using a fixed index like 0 or 1 instead of the positional operator.

Using invalid symbols like #.

The positional $ operator targets the matched element to increment its quantity.

3fill in blank

hard

Fix the error in the update query by correctly using the positional $ operator to set the price of the matched item.

MongoDB

db.collection.updateOne({ 'products.code': 'X123' }, { $set: { 'products.[1].price': 20 } })

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

A0

B$

C1

D*

Attempts:

3 left

💡 Hint

Common Mistakes

Using numeric indices instead of the positional operator.

Using invalid symbols like *.

The positional $ operator must be used to update the matched array element.

4fill in blank

hard

Fill both blanks to update the quantity and price of the matched array element using the positional $ operator.

MongoDB

db.collection.updateOne({ 'orders.id': 101 }, { $set: { 'orders.[1].quantity': 15, 'orders.[2].price': 30 } })

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

A$

B0

C1

D*

Attempts:

3 left

💡 Hint

Common Mistakes

Using different indices for quantity and price fields.

Using invalid symbols instead of $.

Use the positional $ operator in both places to update the matched element's fields.

5fill in blank

hard

Fill all three blanks to update the quantity, price, and status of the matched array element using the positional $ operator.

MongoDB

db.collection.updateOne({ 'inventory.sku': 'A1B2' }, { $set: { 'inventory.[1].quantity': 50, 'inventory.[2].price': 99.99, 'inventory.[3].status': 'in stock' } })

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

A$

B0

C1

D#

Attempts:

3 left

💡 Hint

Common Mistakes

Using numeric indices instead of the positional operator.

Mixing different operators in the same update.

Use the positional $ operator for all fields to update the matched array element correctly.