# MongoDB shell-style statements

# Simple find
db.users.find({})
db.users.find({ "name": "Alice" })

# Find with projection
db.users.find({ "age": { "$gte": 21 } }, { "name": 1, "age": 1 })

# Find with query operators
db.orders.find({ "$or": [{ "status": "A" }, { "qty": { "$lt": 30 } }] })

# Update
db.users.update({ "name": "Alice" }, { "$set": { "age": 31 } })
db.products.update({ "sku": "abc123" }, { "$inc": { "quantity": -1 }, "$set": { "lastSold": "today" } })

# Aggregate
db.orders.aggregate([{ "$match": { "status": "A" } }, { "$group": { "_id": "$cust_id", "total": { "$sum": "$amount" } } }])