Node.js API Masterclass with Express and MongoDB - Populate, Virtuals & Cascade Delete

This video tutorial covers the use of Mongoose virtuals to populate boot camp data in courses and reverse populate boot camps with course arrays. It also demonstrates how to implement cascade delete functionality using Mongoose middleware to ensure that when a boot camp is deleted, all associated courses are also removed. The tutorial provides step-by-step instructions and code examples to help viewers understand and apply these concepts in their own projects.

What is the purpose of using Mongoose virtuals in the context of boot camps and courses?

• To store additional data in the database

• To automatically update related documents

• To create fields that are not stored in the database

• To improve database performance

How can you populate only specific fields of a boot camp in a course document?

• By using a custom query

• By using the 'populate' method with an object specifying fields

• By using the 'populate' method with a string

• By using the 'select' method directly

What is the main challenge when implementing reverse populate with virtuals?

• It can only be used with specific data types

• It involves creating virtual attributes not stored in the database

• It needs a custom schema for each model

• It requires additional database storage

Which method is used to create a virtual field in a Mongoose schema?

• schema.define()

• schema.create()

• schema.virtual()

• schema.add()

What is the purpose of setting 'virtuals' to true in the toJSON and toObject options?

• To enable automatic updates of virtuals

• To improve query performance

• To store virtuals in the database

• To ensure virtuals are included in JSON and object outputs

What is the role of Mongoose middleware in the context of deleting boot camps?

• To prevent deletion of boot camps

• To log all delete operations

• To cascade delete related courses

• To backup data before deletion

Which middleware type is used to perform actions before a document is removed?

• post

• pre

• save

• delete

Why is it necessary to change the delete method to trigger the pre-remove middleware?

• To ensure the middleware runs after deletion

• To allow the use of custom delete logic

• To ensure associated courses are deleted

• To improve performance of delete operations

What method should be used instead of 'findByIdAndDelete' to trigger pre-remove middleware?

• findOneAndDelete

• remove

• deleteOne

• findById

What happens to courses when a boot camp is deleted using the adjusted method?

• Courses are archived

• Courses are moved to a different boot camp

• Courses remain unchanged

• Courses are also deleted