MongoDB Basics for Developers

What is MongoDB?

MongoDB is a document-oriented NoSQL database that stores data in flexible, JSON-like documents. It is ideal for applications with evolving schemas, content management, and real-time analytics.

Installation

curl -fsSL https://www.mongodb.org/static/pgp/server-7.0.asc | sudo gpg --dearmor -o /usr/share/keyrings/mongodb-server-7.0.gpg
echo "deb [ signed-by=/usr/share/keyrings/mongodb-server-7.0.gpg ] https://repo.mongodb.org/apt/ubuntu jammy/mongodb-org/7.0 multiverse" | sudo tee /etc/apt/sources.list.d/mongodb-org-7.0.list
sudo apt update
sudo apt install -y mongodb-org
sudo systemctl enable --now mongod

Basic Operations

# Connect
mongosh

# Create/switch database
use mydb

# Insert documents
db.users.insertOne({ name: "Alice", email: "alice@example.com", age: 30 })
db.users.insertMany([
  { name: "Bob", email: "bob@example.com", age: 25 },
  { name: "Charlie", email: "charlie@example.com", age: 35 }
])

# Find documents
db.users.find()
db.users.find({ age: { $gt: 28 } })
db.users.findOne({ email: "alice@example.com" })

# Update
db.users.updateOne({ name: "Alice" }, { $set: { age: 31 } })

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

Security

# Enable authentication
use admin
db.createUser({
  user: "admin",
  pwd: "secure_password",
  roles: ["root"]
})

Edit /etc/mongod.conf:

security:
  authorization: enabled