Connection & Databases
After installation, you interact with MongoDB using the MongoDB Shell (mongosh) or a driver (like Node.js).
The Connection String
MongoDB uses a URI format for connections:
# Local Connection
mongodb://localhost:27017
# Atlas (Cloud) Connection
mongodb+srv://<username>:<password>@cluster.mongodb.net/myFirstDatabase
Working with Databases
In MongoDB, databases hold collections of documents.
1. Show All Databases
show dbs
2. Create or Switch Database
The `use` command is used to switch to a database. If it doesn't exist, MongoDB creates it when you first save data.
use my_new_db
3. Check Current Database
db
4. Drop Database
db.dropDatabase()
Working with Collections
Collections are similar to tables in RDBMS.
1. Show Collections
show collections
2. Create Collection (Explicitly)
db.createCollection("users")
3. Drop Collection
db.users.drop()
Note: In MongoDB, you don't *have* to create a database or collection explicitly. They are created automatically when you insert the first document.