How to Use deleteMany in MongoDB: Syntax and Examples

In MongoDB, use deleteMany(filter) to remove all documents that match the given filter. This method deletes multiple documents at once and returns a result object with the count of deleted documents.

Syntax

The deleteMany() method takes a filter object to specify which documents to delete. It removes all documents matching this filter from the collection.

• filter: A query object to match documents for deletion.

The method returns a result object containing deletedCount, which shows how many documents were deleted.

mongodb

db.collection.deleteMany(filter)

Example

This example deletes all documents where the field status is "inactive" from the users collection.

javascript

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

async function run() {
  const client = new MongoClient('mongodb://localhost:27017');
  try {
    await client.connect();
    const db = client.db('testdb');
    const users = db.collection('users');

    // Delete all users with status 'inactive'
    const result = await users.deleteMany({ status: 'inactive' });
    console.log(`${result.deletedCount} documents were deleted.`);
  } finally {
    await client.close();
  }
}

run().catch(console.dir);

Output

3 documents were deleted.

Common Pitfalls

Common mistakes when using deleteMany() include:

• Using an empty filter {} unintentionally deletes all documents in the collection.
• Not awaiting the asynchronous operation in Node.js can cause unexpected behavior.
• Confusing deleteMany() with deleteOne(), which deletes only one matching document.

mongodb

/* Wrong: Deletes all documents unintentionally */
db.collection.deleteMany({});

/* Right: Specify a filter to delete only matching documents */
db.collection.deleteMany({ status: 'inactive' });

Quick Reference

Method	Description
deleteMany(filter)	Deletes all documents matching the filter.
deleteOne(filter)	Deletes the first document matching the filter.
filter	A query object to select documents to delete.
deletedCount	Number of documents deleted returned in result.

Key Takeaways

Use deleteMany(filter) to remove all documents matching the filter in a collection.

Always specify a filter to avoid deleting all documents unintentionally.

deleteMany returns a result with deletedCount showing how many documents were removed.

In Node.js, await deleteMany to ensure the operation completes before proceeding.

deleteMany differs from deleteOne, which deletes only a single matching document.