Code
mongodb
// Insert documents
db.users.insertOne({ name: "Alice", age: 30, roles: ["admin"] });
db.users.insertMany([
{ name: "Bob", age: 25, roles: ["user"] },
{ name: "Carol", age: 35, roles: ["user", "editor"] }
]);
// Find with projection and limit
db.users.find({ age: { $gte: 30 } }, { name: 1, _id: 0 }).limit(10);
// Count and findOne
db.users.countDocuments({ "roles": "user" });
db.users.findOne({ name: "Alice" });
// Pretty print
db.users.find().pretty();