ASP.NET Core Web API Interview Question #106

What is the repository pattern, and is it always required with EF Core?

Dependency Injection, Services, EF Core, Async & Data Access Mid-Level Intermediate

Quick Interview Answer

A repository abstracts data-access operations behind an application-specific interface. It can be useful when the domain requires a meaningful persistence abstraction or when multiple data sources must be coordinated.

Detailed Explanation

EF Core's DbContext and DbSet already provide unit-of-work and repository-like capabilities, so adding generic repositories purely as wrappers can create unnecessary indirection. Use repositories when they add a real architectural boundary rather than by default.

Code Example

public interface IOrderRepository
{
    Task<Order?> GetAsync(
        int id,
        CancellationToken token);

    Task AddAsync(
        Order order,
        CancellationToken token);
}