Tutorials ASP.NET Core Web API Tutorial

Singleton vs Scoped vs Transient in ASP.NET Core Web API — Complete Guide

Singleton vs Scoped vs Transient in ASP.NET Core Web API — Complete Guide: free step-by-step lesson with examples, common mistakes, and interview tips — part of ASP.NET Core Web API Tutorial on Toolliyo Academy.

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ASP.NET Core Web API Tutorial · Lesson 27 of 100

Repository Pattern in ASP.NET Core Web API

Beginner ✓IntermediateAdvancedProfessional

Intermediate · 2 — Data & security · ~6 min · Module 3: Entity Framework Core

What is this?

Repository Pattern in ASP.NET Core Web API is a core Web API concept. Learn the idea in plain words first, then run the example in ShopNest.API.

Why should you care?

Interviewers and production teams expect you to explain Repository Pattern in ASP.NET Core Web API clearly — not just copy code from Stack Overflow.

See it live — copy this example

Create a Web API (dotnet new webapi), paste the example, run dotnet run, test in Swagger.

// Repository Pattern in ASP.NET Core Web API — ShopNest.API
[ApiController]
[Route("api/[controller]")]
public class DemoController : ControllerBase
{
    [HttpGet]
    public IActionResult Get() => Ok(new { topic = "Repository Pattern in ASP.NET Core Web API" });
}

Run Example »

Edit the code and click Run — like W3Schools Try it Yourself.

Code
Result

What happened?

  • Study the example line by line.
  • Each part connects to Repository Pattern in ASP.NET Core Web API.
  • Edit one line, run dotnet run, and test in Swagger to see what changes.

Try it yourself

  1. Read what Repository Pattern in ASP.NET Core Web API means in the introduction.
  2. Type the example in ShopNest.API — do not only copy-paste.
  3. Test the endpoint in Swagger or curl.
  4. Change a route URL or DTO property and save — test again in Swagger or curl.
  5. Return the wrong status code on purpose (404 instead of 200) and see what the client shows.

Remember

You learned what Repository Pattern in ASP.NET Core Web API is and when to use it. You ran or traced working API code. Move to the next lesson when you can explain it in your own words.

Interview prep for this lesson

Practice these questions aloud after reading—each links to a full structured answer.

Junior PDF Detailed
What is a REST API?
Short answer: A REST (Representational State Transfer) API is an architectural style for designing networked applications. It uses HTTP methods (GET, POST, PUT, DELETE) to perform operations on resources identified by UR…
Mid PDF Detailed
What are the key principles of REST?
Short answer: Statelessness → Each request is independent; the server doesn’t store client state. Explain a bit more Client-Server Architecture → Separation of concerns between client UI and server logic. Uniform Interfa…
Mid PDF Detailed
Client stores token (localStorage, cookies). Client sends token in Authorization header:?
Short answer: uthorization: Bearer <token> Real-world example (ShopNest) ShopNest mobile app sends a JWT Bearer token. The API validates it and uses the user id from claims to load that user’s cart only. Say this i…
Mid PDF Detailed
How does REST differ from SOAP?
Short answer: REST → Lightweight, uses HTTP, usually JSON, easy to use, stateless. SOAP → Protocol-based, uses XML, more complex, built-in security & transactions. REST is more flexible and widely used for web and mo…
Mid PDF Detailed
Client stores token (localStorage, cookies).?
Short answer: Client sends token in Authorization header: Authorization: Bearer <token> Real-world example (ShopNest) ShopNest exposes REST APIs for cart and checkout. Controllers stay thin; business rules live in…
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ASP.NET Core Web API Tutorial
Course syllabus

ASP.NET Core Web API Tutorial

Module 1: Introduction and Environment Setup
Module 2: Web API Basics
Module 3: Routing
Module 4: Return Types and Status Codes
Module 5: Model Binding
Module 6: Entity Framework Core
Module 7: AutoMapper and Mapperly
Module 8: HTTP Methods
Module 9: Logging
Module 10: Caching
Module 11: FluentValidation
Module 12: Filters
Module 13: Security
Module 14: API Versioning
Module 15: Repository Pattern
Module 16: E-Commerce Real-Time Application
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