4. CRUD Implementation
Build the Task service and expose REST endpoints.
What you'll learn
- The REST concepts that guide the endpoints in this chapter
- How to move from data logic to HTTP endpoints step by step
- Where each part of the CRUD flow (service, controller, routes) will be built
What does CRUD mean?
CRUD stands for Create, Read, Update, and Delete. These four actions cover the core lifecycle of most resources:
- Create – add a new record (e.g.,
POST /tasks). - Read – fetch existing data (e.g.,
GET /tasks). - Update – modify part of a record (e.g.,
PATCH /tasks/:id). - Delete – remove a record (e.g.,
DELETE /tasks/:id).
Every endpoint you’ll build in this chapter maps to one of these operations.
This chapter is split into focused pages:
- REST Basics – plain-language primer on resources, HTTP verbs, and routes.
- Controller + Service Pattern – understand how Nest splits responsibilities before coding.
- Service – implement the database-facing logic with NestJS + MongoDB.
- Controller & Routes – expose that logic over HTTP.
Work through the pages in order. By the time you reach the controller page, the REST vocabulary and service code will already be familiar.
Version control: branch for Chapter 4
Start this chapter from a clean main, then create a new branch so the CRUD work is isolated for review:
git checkout main
git pull origin main
git checkout -b feature/crud-implementationCommit each slice of work (service, controller, tests) as you complete it.