Repository Pattern

Question

Can anyone explain Repository design pattren

Jaish Mathews · Answer

The Repository Design Pattern is used to abstract the data layer, making it easier to decouple the business logic and the data access logic. It acts as a mediator between the domain and the data mapping layers. The primary goal is to create a centralized data access logic that can be reused across the application. Key Benefits Abstraction : Hides the details of data persistence. Testability : Easier to mock data repositories for unit testing. Maintainability : Encapsulates data access logic, making changes easier. Consistency : Provides a consistent interface for accessing data. C# Example Scenario Let's create a simple example where we manage a list of products using the Repository Pattern. Step 1: Define the Entity public class Product { public int Id { get; set; } public string Name { get; set; } public decimal Price { get; set; } } Step 2: Define the Repository Interface public interface IProductRepository { IEnumerable GetAllProducts(); Product GetProductById(int id); void AddProduct(Product product); void UpdateProduct(Product product); void DeleteProduct(int id); } Step 3: Implement the Repository using System.Collections.Generic; using System.Linq; public class ProductRepository : IProductRepository { private readonly List _products = new List (); public IEnumerable GetAllProducts() { return _products; } public Product GetProductById(int id) { return _products.FirstOrDefault(p => p.Id == id); } public void AddProduct(Product product) { _products.Add(product); } public void UpdateProduct(Product product) { var existingProduct = GetProductById(product.Id); if (existingProduct != null) { existingProduct.Name = product.Name; existingProduct.Price = product.Price; } } public void DeleteProduct(int id) { var product = GetProductById(id); if (product != null) { _products.Remove(product); } } } Step 4: Use the Repository in a Service public class ProductService { private readonly IProductRepository _productRepository; public ProductService(IProductRepository productRepository) { _productRepository = productRepository; } public void DisplayAllProducts() { var products = _productRepository.GetAllProducts(); foreach (var product in products) { Console.WriteLine($"ID: {product.Id}, Name: {product.Name}, Price: {product.Price}"); } } public void AddSampleProduct() { _productRepository.AddProduct(new Product { Id = 1, Name = "Laptop", Price = 75000 }); } } Step 5: Dependency Injection and Usage class Program { static void Main(string[] args) { IProductRepository productRepository = new ProductRepository(); var productService = new ProductService(productRepository); productService.AddSampleProduct(); productService.DisplayAllProducts(); } } Real-Time References E-commerce Systems : Repository pattern is used to manage products, customers, orders, and inventory data, abstracting the database interaction. Banking Applications : Managing accounts, transactions, and customers using repositories ensures modularity and easy testing. Healthcare Systems : Data access layers for patient records, appointments, and billing use repositories for efficient access and maintenance. Best Practices Combine the Repository pattern with the Unit of Work pattern to handle transactions. Use dependency injection to inject repository instances. Avoid creating overly complex repository methods that duplicate logic better suited for services. This approach ensures modular, testable, and maintainable code for any application.

Jignesh Kumar · Answer

Hello Kiran, You can find good resources as below to work with generic repository patterns, https://codewithmukesh.com/blog/repository-pattern-in-aspnet-core/ https://codingblast.com/entity-framework-core-generic-repository/

Repository Pattern

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