Projection for reducing data transfer in MongoDB - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to project only the 'name' field from the 'users' collection.

MongoDB

db.users.find({}, { [1]: 1 })

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

Aaddress

Bname

Cemail

Dage

Attempts:

3 left

💡 Hint

Common Mistakes

Using 0 instead of 1 to include fields

Forgetting to specify the field name in the projection

The projection specifies which fields to include. Here, we include only the 'name' field.

2fill in blank

medium

Complete the code to exclude the '_id' field from the results.

MongoDB

db.products.find({}, { [1]: 0 })

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

Aname

Bprice

C_id

Dcategory

Attempts:

3 left

💡 Hint

Common Mistakes

Trying to exclude fields by setting them to 1

Not excluding '_id' when only other fields are projected

Setting '_id' to 0 excludes it from the returned documents.

3fill in blank

hard

Fix the error in the projection to include only 'title' and 'author' fields.

MongoDB

db.books.find({}, { title: 1, [1]: 1, _id: 0 })

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

Agenre

Bpublisher

Cyear

Dauthor

Attempts:

3 left

💡 Hint

Common Mistakes

Including fields not requested

Forgetting to exclude '_id' if not needed

To include 'author' along with 'title', set 'author' to 1 in the projection.

4fill in blank

hard

Fill both blanks to project 'username' and exclude '_id' in the query.

MongoDB

db.accounts.find({}, { [1]: 1, [2]: 0 })

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

Ausername

Bemail

C_id

Dpassword

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing up inclusion and exclusion values

Trying to include and exclude fields at the same time incorrectly

Set 'username' to 1 to include it, and '_id' to 0 to exclude it.

5fill in blank

hard

Fill all three blanks to project 'firstName', 'lastName', and exclude '_id' in the query.

MongoDB

db.employees.find({}, { [1]: 1, [2]: 1, [3]: 0 })

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

AfirstName

BlastName

C_id

Ddepartment

Attempts:

3 left

💡 Hint

Common Mistakes

Including '_id' by mistake

Using wrong field names in projection

Include 'firstName' and 'lastName' by setting them to 1, and exclude '_id' by setting it to 0.