Cách lấy giá trị con trỏ (cursor) trong MongoDB

Sử dụng phương thức hasNext() và next() để lặp qua cursor trả về từ find(). Tạo collection:

> db.demo191.insertOne({ "EmployeeId": 1, "EmployeeName": "Chris Brown" });
{ "acknowledged": true, "insertedId": ObjectId("5e3ad95303d395bdc21346c5") }
> db.demo191.insertOne({ "EmployeeId": 2, "EmployeeName": "David Miller" });
{ "acknowledged": true, "insertedId": ObjectId("5e3ad95f03d395bdc21346c6") }
> db.demo191.insertOne({ "EmployeeId": 1, "EmployeeName": "John Doe" });
{ "acknowledged": true, "insertedId": ObjectId("5e3ad96803d395bdc21346c7") }
> db.demo191.insertOne({ "EmployeeId": 1, "EmployeeName": "John Smith" });
{ "acknowledged": true, "insertedId": ObjectId("5e3ad97003d395bdc21346c8") }

Hiển thị document.

Lặp cursor in từng document có EmployeeId=1:

> var cursor = db.demo191.find({ "EmployeeId": 1 });
> while (cursor.hasNext()) {
  print(tojson(cursor.next()));
}

Kết quả (3 document):

{ "_id": ObjectId("5e3ad95303d395bdc21346c5"), "EmployeeId": 1, "EmployeeName": "Chris Brown" }
{ "_id": ObjectId("5e3ad96803d395bdc21346c7"), "EmployeeId": 1, "EmployeeName": "John Doe" }
{ "_id": ObjectId("5e3ad97003d395bdc21346c8"), "EmployeeId": 1, "EmployeeName": "John Smith" }