Data Deletion Strategies in MongoDB

Introduction

Data deletion in MongoDB is essential for maintaining data integrity and optimizing storage. This lesson will cover various data deletion strategies, including methods, best practices, and common scenarios for data removal.

Deletion Methods

MongoDB provides several methods to delete documents from a collection:

Code Examples

const { MongoClient } = require('mongodb');

async function run() {
    const client = new MongoClient('mongodb://localhost:27017');
    await client.connect();
    const database = client.db('myDatabase');
    const collection = database.collection('myCollection');

    // Delete a single document
    const deleteResult = await collection.deleteOne({ name: 'John' });
    console.log(`Deleted ${deleteResult.deletedCount} document(s)`);

    // Delete multiple documents
    const deleteManyResult = await collection.deleteMany({ age: { $gt: 30 } });
    console.log(`Deleted ${deleteManyResult.deletedCount} document(s)`);

    await client.close();
}
run();

Best Practices

• Use filters carefully to avoid unintentional deletions.
• Implement soft deletes by adding a field (e.g., `isDeleted`) instead of hard deleting documents.
• Regularly monitor your databases for orphaned documents.
• Consider setting up a TTL (Time to Live) index for automatic document expiration.

FAQ