MongoDB is a document-oriented NoSQL database that stores data in JSON format (BSON) within flexible collections.

🤔 Why MongoDB?

MongoDB is for:

• 📄 JSON data - Store JSON directly like in JavaScript
• 🚀 Rapid development - No need to create tables in advance
• 🔄 Flexible structure - Data can change shape
• ⚡ Simple - Closer to programming

Use it for:

• REST APIs (JSON data)
• Mobile applications
• Storing logs, events
• Quick prototypes
• When data doesn’t fit in a spreadsheet

🚀 Installation

📌 System	🧠 Command
🐧 Ubuntu/Debian	sudo apt install mongodb-server mongodb-clients
🎩 CentOS/RHEL	sudo yum install mongodb-org
🍎 macOS (Homebrew)	brew install mongodb-community
🐳 Docker	docker run -d mongo:7
🏢 Official version	mongodb.com/try/download

⚙️ Basic Configuration

📌 Action	🧠 Command
▶️ Start MongoDB	sudo systemctl start mongod
🔄 Enable at boot	sudo systemctl enable mongod
🔗 Connect	mongosh (or mongo)
📋 View databases	show dbs
🔗 Use a database	use myapp
🚪 Exit mongosh	quit() (or Ctrl+C)

🗄️ Database Management

📌 Action	🧠 Command
📋 List databases	show dbs
🆕 Create/use a database	use myapp
📊 Current database	db.getName()
🗑️ Delete current database	db.dropDatabase()
📊 Database statistics	db.stats()
💾 Database size	db.stats().dataSize

📋 Collection Management

📌 Action	🧠 Command
📋 List collections	show collections
🆕 Create a collection	db.createCollection("users")
🗑️ Delete a collection	db.users.drop()
📊 Collection statistics	db.users.stats()
📖 Count documents	db.users.countDocuments()
🔍 First document	db.users.findOne()

👥 User Management

📌 Action	🧠 Command
👤 Create an admin	db.createUser({user:"admin", pwd:"password", roles:["root"]})
👤 Create read-only user	db.createUser({user:"reader", pwd:"pwd", roles:["read"]})
👤 Create read/write user	db.createUser({user:"editor", pwd:"pwd", roles:["readWrite"]})
📋 List users	db.getUsers()
🗑️ Delete a user	db.dropUser("reader")
🔐 Enable authentication	Edit /etc/mongod.conf: security.authorization: enabled

💾 Backup and Restore

📌 Action	🧠 Command
💾 Backup a database	mongodump --db myapp --out ./backup/
💾 Backup everything	mongodump --out ./backup/
📥 Restore a database	mongorestore --db myapp ./backup/myapp/
📥 Restore everything	mongorestore ./backup/
🗜️ Export JSON	mongoexport --db myapp --collection users --out users.json
📦 Import JSON	mongoimport --db myapp --collection users --file users.json

🔍 Monitoring and Debug

📌 Action	🧠 Command
📊 Server status	db.serverStatus()
🔗 Active connections	db.serverStatus().connections
🐌 Profiler (slow queries)	db.setProfilingLevel(2)
📈 View profile	db.system.profile.find()
💾 Memory usage	db.serverStatus().mem
🔧 Current operations	db.currentOp()