Soft delete pattern in MongoDB - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the soft delete pattern in MongoDB?

Soft delete means marking a document as deleted without removing it from the database. This is usually done by adding a field like isDeleted: true instead of deleting the document.

beginner

Why use soft delete instead of hard delete?

Soft delete helps keep data for recovery, auditing, or history. It avoids losing data permanently and allows easy undo of deletions.

beginner

How do you query only active (not deleted) documents in MongoDB with soft delete?

Add a filter like { isDeleted: { $ne: true } } to your query to exclude documents marked as deleted.

beginner

What field is commonly added to implement soft delete in MongoDB?

A boolean field like isDeleted or a date field like deletedAt is added to mark deletion status.

intermediate

How can you permanently remove soft deleted documents later?

Use a query like db.collection.deleteMany({ isDeleted: true }) to clean up documents marked as deleted.

What does soft delete do in MongoDB?

A Marks documents as deleted without removing them

B Immediately removes documents from the database

C Backs up documents before deleting

D Encrypts documents before deletion

Soft delete marks documents as deleted (e.g., with isDeleted: true) but keeps them in the database.

Which field is commonly used to mark a document as deleted in soft delete?

A username

B createdAt

C isDeleted

D password

The isDeleted field is commonly added to indicate if a document is soft deleted.

How do you exclude soft deleted documents in a MongoDB query?

A { isDeleted: false }

B { isDeleted: true }

C { deletedAt: null }

D { isDeleted: { $ne: true } }

Using { isDeleted: { $ne: true } } filters out documents marked as deleted.

What is a benefit of using soft delete?

A Allows data recovery after deletion

B Makes queries faster

C Reduces database size

D Encrypts data automatically

Soft delete keeps data so you can recover it if needed.

How can you permanently remove soft deleted documents?

A Insert new documents

B Use deleteMany with { isDeleted: true }

C Update documents to isDeleted: false

D Use findOneAndUpdate

deleteMany with { isDeleted: true } removes all soft deleted documents permanently.

Explain the soft delete pattern in MongoDB and why it is useful.

Think about how you keep old files instead of throwing them away immediately.

Describe how to query only active documents when using soft delete in MongoDB.

How do you find files that are not marked as deleted?