Step 1: Switch to a Database

Before working with collections, ensure you are in the right database. If you haven't created one, switch to a new database using:

use myDatabase

Step 2: Create a Collection (Optional)

Collections in MongoDB are created automatically when you insert data. However, you can manually create a collection with specific options:

db.createCollection("users")

Step 3: Insert Documents into a Collection

To add a single document to the users collection:

db.users.insertOne({ name: "John Doe", age: 30, city: "New York" })

To insert multiple documents:

db.users.insertMany([
  { name: "Alice", age: 25, city: "London" },
  { name: "Bob", age: 28, city: "Toronto" }
])

Step 4: Retrieve Data from a Collection

To fetch all documents from a collection:

db.users.find()

To find specific users, such as those in London:

db.users.find({ city: "London" })

To format the output for better readability:

db.users.find().pretty()

Step 5: Update Documents in a Collection

To update a single document:

db.users.updateOne({ name: "Alice" }, { $set: { age: 26 } })

To update multiple documents:

db.users.updateMany({ city: "Toronto" }, { $set: { country: "Canada" } })

Step 6: Delete Documents from a Collection

To delete a single document:

db.users.deleteOne({ name: "Bob" })

To delete multiple documents:

db.users.deleteMany({ city: "London" })

Step 7: Drop a Collection

If you want to remove an entire collection:

db.users.drop()

Conclusion

You’ve now learned how to work with MongoDB collections. Remember:
✅ Collections store multiple documents.
✅ They are created automatically when data is inserted.
✅ You can insert, retrieve, update, and delete documents easily.

Now you can start managing data efficiently in MongoDB! 🚀