Install MongoDB, understand the document model, and perform all four CRUD operations from the shell and from Node.js.
MongoDB stores data as BSON (Binary JSON) documents. A document is like a row in SQL — but it can have nested objects and arrays. No fixed schema required.
# Mac: brew install mongodb-community # Linux: see mongodb.com/docs/manual/installation # Or use MongoDB Atlas free tier (cloud) # Start the shell mongosh
// Select database (creates if doesn't exist)
use myapp
// INSERT
db.users.insertOne({ name: 'Alice', age: 28, role: 'admin' })
db.users.insertMany([ { name: 'Bob', age: 32 }, { name: 'Carol', age: 25 }
])
// FIND
db.users.find() // all documents
db.users.findOne({ name: 'Alice' })
db.users.find({ age: { $gte: 28 } }) // age >= 28
// UPDATE
db.users.updateOne( { name: 'Alice' }, { $set: { role: 'superadmin' } }
)
// DELETE
db.users.deleteOne({ name: 'Carol' })
db.users.deleteMany({ age: { $lt: 18 } }) _id field automatically. It's a 12-byte ObjectId that encodes a timestamp. You can use it to sort documents by creation time without storing a separate createdAt field: .sort({ _id: -1 }).Before moving on, make sure you can answer these without looking: