ASP.NET Core Web API - Build an API from Scratch

Explore the client–server request workflow of a web API, including a get /courses call processed by a database repository, returning 200 ok or 500 internal server error.

Explore the http request-response cycle and core web api operations (get, post, put, delete, patch) along with common status codes for success and errors in a college management system project.

Delete the weather forecast controller and create a new courses controller derived from the controller base class, adding a constructor for dependency injection plus the controller and route attribute.

Implement the get all courses operation in an in-memory CMS repository using a DTO mapping strategy, exposing via ASP.NET Core Web API and validating with Postman on port 5000.

Build an ASP.NET Core web API by creating a controller with routing, define actions with HTTP verbs, inject repositories (including in-memory), and map data models to DTOs to fetch courses.

Use action result of T to return any type, with implicit cast handled by ASP.NET; for enumerables, return a list of T to support status codes, including internal server error.

Implement get operation to fetch a course by id via http get route, validate existence, retrieve a course from the repository, map to the course model, and test with postman.

Implement get, put, and delete operations for an individual item using http get with route parameters and simple Linq queries. This section completes the item APIs and previews association APIs.

Explore association APIs in a web API by exposing collection endpoints tied to items, using get and post to fetch related data like students in a course, with delete optional.

Add versions to actions within a controller by duplicating actions and mapping them to specific API versions, such as 3.0, 2.0, or 1.0.