E-commerce API

A RESTful API built with ASP.NET Core for managing an e-commerce system with products, categories, and sales tracking.

Features

• Product Management: CRUD operations for products with inventory tracking
• Category Management: Organize products into categories
• Sales Processing: Create and track sales with automatic inventory deduction
• Soft Delete: Entities are soft-deleted, allowing data recovery
• Pagination: Efficient data retrieval with pagination support
• Result Pattern: Consistent error handling and response formatting
• Global Exception Handling: Middleware for centralized error handling across all requests
• Input Validation: Request validation using FluentValidation with descriptive error messages
• API Versioning: URL segment versioning via Asp.Versioning (current version: v1)

Architecture

This project follows Clean Architecture principles with clear separation of concerns:

EcommerceApi/
├── Ecommerce.Core/          # Domain layer (Models, DTOs, Interfaces)
│   ├── Models/              # Domain entities
│   ├── DTOs/                # Data Transfer Objects
│   ├── Interfaces/          # Service and repository contracts
│   ├── Utilities/           # Shared utilities (Result, Pagination)
|   └── Validators/          # FluentValidation validators
├── Ecommerce.Data/          # Data access layer
│   ├── Repositories/        # Repository implementations
│   ├── Migrations/          # EF Core migrations
│   └── AppDbContext.cs      # Database context
├── Ecommerce.Services/      # Business logic layer
│   ├── CategoryService.cs
│   ├── ProductService.cs
│   └── SaleService.cs
└── Ecommerce.Web/           # Presentation layer (API)
    ├── Controllers/         # API controllers
    ├── Extensions/          # Global Exception handler
    └── Program.cs           # Application entry point

Technologies

• .NET 10.0
• ASP.NET Core Web API
• Entity Framework Core with SQL Server
• Repository Pattern with Unit of Work
• Dependency Injection
• OpenAPI/Postman for API documentation
• FluentValidation for input validation
• Asp.Versioning for API versioning

Getting Started

Prerequisites

• .NET 10 SDK
• SQL Server (LocalDB, Express, or full version)
• Visual Studio 2022 / JetBrains Rider / VS Code

Installation

1. Clone the repository

   git clone <repository-url>
   cd EcommerceApi

2. Configure the database connection

   Update the connection string in Ecommerce.Web/appsettings.json:

   {
     "ConnectionStrings": {
       "DefaultConnection": "Server=(localdb)\\mssqllocaldb;Database=EcommerceDb;Trusted_Connection=true;"
     }
   }

3. Apply database migrations

   cd Ecommerce.Web
   dotnet ef database update

4. Run the application

   dotnet run --project Ecommerce.Web

5. Access the API

   • API: http://localhost:5248
   • OpenAPI UI: Navigate to /openapi/v1.json (in development mode)

API Endpoints

Categories

Method	Endpoint	Description
GET	/api/v1/category	Get all categories
GET	/api/v1/category/{id}	Get category by ID
POST	/api/v1/category	Create a new category
PUT	/api/v1/category/{id}	Update a category
DELETE	/api/v1/category/{id}	Delete a category (soft delete)

Products

Method	Endpoint	Description
GET	/api/v1/product?pageNumber=1&pageSize=10	Get all products (paginated)
GET	/api/v1/product/{id}	Get product by ID
POST	/api/v1/product	Create a new product
PUT	/api/v1/product/{id}	Update a product
DELETE	/api/v1/product/{id}	Delete a product (soft delete)

Sales

Method	Endpoint	Description
GET	/api/v1/sale?pageNumber=1&pageSize=10	Get all sales (paginated)
GET	/api/v1/sale/{id}	Get sale by ID with items
POST	/api/v1/sale	Create a new sale

API Usage Examples

Create a Category

POST /api/v1/category
Content-Type: application/json
 
{
  "name": "Electronics",
  "description": "Electronic devices and gadgets"
}

Create a Product

POST /api/v1/product
Content-Type: application/json
 
{
  "name": "Laptop",
  "description": "High-performance laptop",
  "price": 999.99,
  "quantity": 50,
  "imageUrl": "https://example.com/laptop.jpg",
  "categoryId": 1
}

Create a Sale

POST /api/v1/sale
Content-Type: application/json
 
{
  "items": [
    {
      "productId": 1,
      "quantity": 2
    },
    {
      "productId": 2,
      "quantity": 1
    }
  ]
}

Note: Creating a sale automatically:

• Validates product availability
• Deducts inventory quantities
• Captures prices at time of sale
• Calculates total price

Pagination

Products and Sales support pagination:

GET /api/v1/product?pageNumber=2&pageSize=20

Database Schema

Core Entities

Category

• Id (int, PK)
• Name (string, required)
• Description (string, nullable)
• IsDeleted (bool)
• DeletedAt (DateTime?)

Product

• Id (int, PK)
• Name (string, required)
• Price (decimal(18,2))
• Quantity (int)
• Description (string, nullable)
• ImageUrl (string, nullable)
• CategoryId (int, FK)
• IsDeleted (bool)
• DeletedAt (DateTime?)

Sale

• Id (int, PK)
• CreationDate (DateTime)
• TotalPrice (decimal(18,2))
• IsDeleted (bool)
• DeletedAt (DateTime?)

SaleItem (Many-to-Many)

• SaleId (int, PK, FK)
• ProductId (int, PK, FK)
• Quantity (int)
• UnitPriceAtTimeOfSale (decimal(18,2))

Design Patterns

• Repository Pattern: Abstracts data access logic
• Unit of Work: Manages transactions across repositories
• Result Pattern: Standardized success/failure responses
• Dependency Injection: Loose coupling between layers
• Soft Delete: Data preservation with ISoftDeletable interface

Development

Project Structure

• Ecommerce.Core: Contains business entities, DTOs, and interfaces (no dependencies)
• Ecommerce.Data: Implements data access using EF Core
• Ecommerce.Services: Implements business logic
• Ecommerce.Web: ASP.NET Core Web API project

Adding Migrations

dotnet ef migrations add MigrationName --project Ecommerce.Data --startup-project Ecommerce.Web

Applying Migrations

dotnet ef database update --project Ecommerce.Data --startup-project Ecommerce.Web

Error Handling

The API uses a custom Result<T> pattern for consistent error responses:

Success Response:

{
  "data": { ... },
  "isSuccess": true,
  "message": null
}

Error Response:

{
  "data": null,
  "isSuccess": false,
  "message": "Error description"
}

Validation

Input validation is handled by FluentValidation and covers:

• Required fields (e.g. product name, category name)
• Positive quantity values
• Price must be greater than zero
• Category existence when creating/updating products
• Product existence and stock availability when creating sales

API Versioning

This API uses URL segment versioning via the Asp.Versioning package. The version is embedded directly in the route:

/api/v{version}/{resource}

Current version: v1

All endpoints are prefixed with /api/v1/. When new versions are introduced, older versions remain accessible at their original paths to avoid breaking changes.

Future Enhancements

• Add authentication & authorization (JWT) (Currently Working On)
• Implement logging (Serilog)
• Add unit and integration tests
• Implement caching for frequently accessed data
• Implement rate limiting
• Add CORS configuration
• Add filtering and sorting capabilities
• Implement search functionality

Contributing

This is a study project from The C# Academy. Feel free to fork and experiment!