Delete all documents in collection in MongoDB - Mini Project: Build & Apply

Delete All Documents in a MongoDB Collection

📖 Scenario: You are managing a MongoDB database for a small online bookstore. Sometimes, you need to clear out all the book records to reset the collection before adding new data.

🎯 Goal: Learn how to delete all documents from a MongoDB collection using a simple command.

📋 What You'll Learn

Create a MongoDB collection named books with some sample documents.

Set up a variable to reference the books collection.

Use the correct MongoDB command to delete all documents in the books collection.

Confirm the deletion command is correctly structured.

💡 Why This Matters

🌍 Real World

Clearing out old or test data from a MongoDB collection is common when resetting databases or cleaning up after tests.

💼 Career

Database administrators and backend developers often need to delete data efficiently and safely using commands like 'deleteMany'.

1

Create the books collection with sample documents

Create a MongoDB collection called books and insert these exact documents: { title: "Book A", author: "Author 1" }, { title: "Book B", author: "Author 2" }, and { title: "Book C", author: "Author 3" }.

MongoDB

// Insert the sample documents into the books collection
// Your code here

Need a hint?

Use db.books.insertMany([...]) to add multiple documents at once.

2

Set a variable to reference the books collection

Create a variable called collection and set it to db.books to reference the books collection.

MongoDB

db.books.insertMany([
  { title: "Book A", author: "Author 1" },
  { title: "Book B", author: "Author 2" },
  { title: "Book C", author: "Author 3" }
])

// Create a variable named collection to reference db.books
// Your code here

Need a hint?

Use const collection = db.books to create the variable.

3

Delete all documents from the books collection

Use the deleteMany method on the collection variable with an empty filter {} to delete all documents in the collection.

MongoDB

db.books.insertMany([
  { title: "Book A", author: "Author 1" },
  { title: "Book B", author: "Author 2" },
  { title: "Book C", author: "Author 3" }
])

const collection = db.books

// Use collection.deleteMany({}) to delete all documents
// Your code here

Need a hint?

Use collection.deleteMany({}) to remove all documents.

4

Confirm the deletion command is complete

Add a semicolon ; at the end of the collection.deleteMany({}) command to complete the statement.

MongoDB

db.books.insertMany([
  { title: "Book A", author: "Author 1" },
  { title: "Book B", author: "Author 2" },
  { title: "Book C", author: "Author 3" }
])

const collection = db.books

collection.deleteMany({})
// Add a semicolon at the end of the deleteMany command
// Your code here

Need a hint?

Remember to end statements with a semicolon ; in JavaScript.