Querying Documents

This video tutorial covers reading operations in MongoDB, focusing on the find and findOne methods. It explains how to query documents by various fields, handle query results, and use cursors for more advanced data retrieval. The tutorial includes a practical challenge to reinforce learning, where viewers practice fetching documents from a tasks collection using the discussed methods.

What is the primary purpose of transitioning from 'create' to 'read' in MongoDB?

• To update documents

• To delete documents

• To insert new documents

• To fetch and view documents

Which method is used to fetch a single document by a specific field in MongoDB?

• find

• findOne

• insertOne

• deleteOne

What happens if findOne does not find any matching documents?

• It returns an empty array

• It stops the program

• It throws an error

• It returns null

Why is it necessary to use ObjectID when searching by ID in MongoDB?

• Because IDs are stored as strings

• Because IDs are stored as arrays

• Because IDs are stored as binary data

• Because IDs are stored as integers

What is a cursor in MongoDB?

• A pointer to data in the database

• A method to delete data

• A tool to update data

• A function to insert data

Which method is used to convert a cursor to an array of documents?

• aggregate

• limit

• count

• toArray

What is the advantage of using a cursor in MongoDB?

• It simplifies data deletion

• It provides flexibility in data retrieval

• It enables fetching all documents at once

• It allows for faster data insertion

In the challenge, what is the first step to find a task by ID?

• Use the find method

• Use the findOne method

• Use the delete method

• Use the update method

What criteria is used to find incomplete tasks in the challenge?

• Tasks with a specific name

• Tasks with a specific ID

• Tasks with a completed value of false

• Tasks with a completed value of true

What is the expected output when fetching tasks that are not completed?

• An array of incomplete tasks

• An array of completed tasks

• A count of all tasks

• A single document