Soft delete pattern in MongoDB - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to mark a document as deleted by setting the 'deleted' field to true.

MongoDB

db.users.updateOne({ _id: userId }, { $set: { deleted: [1] } })

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

Aundefined

Bfalse

Cnull

Dtrue

Attempts:

3 left

💡 Hint

Common Mistakes

Setting 'deleted' to false instead of true.

Using null or undefined which do not indicate deletion.

Setting the 'deleted' field to true marks the document as soft deleted.

2fill in blank

medium

Complete the query to find only documents that are not soft deleted.

MongoDB

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

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

Atrue

Bnull

Cfalse

D{}

Attempts:

3 left

💡 Hint

Common Mistakes

Searching for deleted: true which returns deleted documents.

Using null or empty object which does not filter correctly.

Documents with 'deleted' set to false are active (not deleted).

3fill in blank

hard

Fix the error in the update query to soft delete a document by setting 'deleted' to true.

MongoDB

db.users.updateOne({ _id: userId }, { $set: { deleted: [1] } })

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

Anull

Btrue

C1

D"true"

Attempts:

3 left

💡 Hint

Common Mistakes

Using "true" as a string instead of boolean true.

Using 1 which is a number, not a boolean.

The value should be the boolean true, not a string or number.

4fill in blank

hard

Fill both blanks to query active users and sort them by creation date descending.

MongoDB

db.users.find({ deleted: [1] }).sort({ createdAt: [2] })

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

Afalse

Btrue

C-1

D1

Attempts:

3 left

💡 Hint

Common Mistakes

Using deleted: true to find deleted users.

Sorting ascending (1) instead of descending (-1).

We find users where 'deleted' is false (active users) and sort by 'createdAt' descending using -1.

5fill in blank

hard

Fill all three blanks to update a document's 'deleted' status, set 'deletedAt' timestamp, and exclude deleted documents in a query.

MongoDB

db.users.updateOne({ _id: userId }, { $set: { deleted: [1], deletedAt: [2] } });
db.users.find({ deleted: [3] })

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

Atrue

Bnew Date()

Cfalse

Dnull

Attempts:

3 left

💡 Hint

Common Mistakes

Not setting deletedAt timestamp.

Querying for deleted: true instead of false.

Set 'deleted' to true and 'deletedAt' to the current date. Then query documents where 'deleted' is false to exclude deleted ones.