Subset pattern for large documents in MongoDB - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to project only the 'name' field from the documents.

MongoDB

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

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

Aname

Bage

Caddress

Demail

Attempts:

3 left

💡 Hint

Common Mistakes

Using 0 instead of 1 to include a field

Forgetting to specify the field name

Including multiple fields when only one is needed

To get only the 'name' field, you specify it with 1 in the projection part of the find query.

2fill in blank

medium

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

MongoDB

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

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

Aemail

Bname

C_id

Dage

Attempts:

3 left

💡 Hint

Common Mistakes

Trying to exclude fields by setting them to 1

Not excluding '_id' when it's not needed

Using incorrect field names

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

3fill in blank

hard

Fix the error in the projection to include 'name' and exclude '_id'.

MongoDB

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

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

Aemail

Bname

C_id

Dage

Attempts:

3 left

💡 Hint

Common Mistakes

Trying to include and exclude the same field

Using wrong field names

Not setting the correct values for inclusion/exclusion

You cannot include '_id' and exclude it at the same time. To include 'name' and exclude '_id', specify 'name: 1' and '_id: 0'.

4fill in blank

hard

Fill both blanks to project only 'name' and 'email' fields, excluding '_id'.

MongoDB

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

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

Aname

Bage

Cemail

Daddress

Attempts:

3 left

💡 Hint

Common Mistakes

Including '_id' by mistake

Using 0 instead of 1 for included fields

Forgetting to include all desired fields

To include multiple fields, list each with 1 in the projection. Excluding '_id' is done by setting it to 0.

5fill in blank

hard

Fill all three blanks to project 'name' in uppercase, include 'email', and exclude '_id'.

MongoDB

db.collection.aggregate([{ $project: { [1]: { $toUpper: "$name" }, [2]: 1, [3]: 0 } }])

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

AnameUpper

Bemail

C_id

Dname

Attempts:

3 left

💡 Hint

Common Mistakes

Using the original 'name' field instead of a new field

Not excluding '_id'

Incorrect field names in projection

Use $project to create a new field 'nameUpper' with uppercase 'name', include 'email', and exclude '_id' by setting it to 0.