Deleting Documents in MongoDB: A Comprehensive Guide

Learn how to effectively remove documents from MongoDB collections using the deleteOne() and deleteMany() methods. This guide will provide you with the necessary knowledge and examples to perform document deletion operations in your MongoDB applications.

MongoDB: Delete Documents in a Collection

MongoDB offers methods to delete documents from a collection. You can use deleteOne() to delete the first matching document or deleteMany() to delete all matching documents.

Delete One Document

Use db.collection.deleteOne() to delete the first document that matches the filter criteria.

db.collection.deleteOne(filter, options)

Parameters:

• filter: Criteria to match documents, similar to find() method.
• options: Optional. Includes writeConcern, collation, and hint.

Insert sample documents into the employees collection:

db.employees.insertMany([
    { _id: 1, firstName: "John", lastName: "Doe", email: "john.doe@example.com", salary: 5000 },
    { _id: 2, firstName: "Jane", lastName: "Smith", email: "jane.smith@example.com", salary: 8000 },
    { _id: 3, firstName: "Emily", lastName: "Johnson", email: "emily.johnson@example.com", salary: 7500 },
    { _id: 4, firstName: "Michael", lastName: "Brown", email: "michael.brown@example.com", salary: 7000 },
    { _id: 5, firstName: "Sarah", lastName: "Davis", email: "sarah.davis@example.com", salary: 4500 },
    { _id: 6, firstName: "David", lastName: "Wilson", email: "david.wilson@example.com", salary: 7000 }
])

Example: Delete a Single Document

db.employees.deleteOne({ salary: 7000 })

{ acknowledged: true, deletedCount: 1 }

Delete Many Documents

Use db.collection.deleteMany() to delete all documents matching the filter criteria.

db.collection.deleteMany(filter, options)

Parameters:

• filter: Criteria to match documents, similar to find() method.
• options: Optional. Includes writeConcern, collation, and hint.

Example: Delete Documents with Salary 7000

db.employees.deleteMany({ salary: 7000 })

{ acknowledged: true, deletedCount: 2 }

Example: Delete Documents with Salary Less than 7000

db.employees.deleteMany({ salary: { $lt: 7000 } })

{ acknowledged: true, deletedCount: 2 }

Example: Delete All Documents

db.employees.deleteMany({})

{ acknowledged: true, deletedCount: 6 }