Generic Repositories for .NET

Generic repository abstractions and Entity Framework Core implementations for .NET 10.

Features

• Read-only and read/write repositories — separate contracts enforce read intent at the type level
• Unit of Work via IDataAccessContext — multiple repositories share the same DbContext; a single SaveChangesAsync call persists all changes
• No-tracking by default — RepositoryReadOnly queries use AsNoTrackingWithIdentityResolution

Projects

Project	Description
GenericRepositories.Abstractions	Interfaces: IDataAccessContext, IRepositoryReadOnly<TEntity>, IRepository<TEntity>
GenericRepositories.EntityFramework	EF Core implementations: DataAccessContext, DataAccessContextReadOnly, Repository, RepositoryReadOnly
GenericRepositories.SampleApi	Minimal API CRUD example with EF Core InMemory provider

Usage

1. Create app-specific wrappers

public class AppDataAccessContext(AppDbContext dbContext)
    : DataAccessContext<AppDbContext>(dbContext);

public class AppDataAccessContextReadOnly(AppDbContext dbContext)
    : DataAccessContextReadOnly<AppDbContext>(dbContext);

public class AppRepository<TEntity>(AppDataAccessContext dataAccessContext)
    : Repository<AppDbContext, TEntity>(dataAccessContext)
    where TEntity : class;

public class AppRepositoryReadOnly<TEntity>(AppDataAccessContextReadOnly dataAccessContext)
    : RepositoryReadOnly<AppDbContext, TEntity>(dataAccessContext)
    where TEntity : class;

2. Register in DI

builder.Services.AddDbContext<AppDbContext>(options => ...);

builder.Services.AddScoped<AppDataAccessContext>();
builder.Services.AddScoped<AppDataAccessContextReadOnly>();
builder.Services.AddScoped(typeof(IRepository<>), typeof(AppRepository<>));
builder.Services.AddScoped(typeof(IRepositoryReadOnly<>), typeof(AppRepositoryReadOnly<>));

3. Inject and use

// Read-only — no-tracking queries, SaveChangesAsync throws NotSupportedException
app.MapGet("/products", async (IRepositoryReadOnly<Product> repository, CancellationToken ct) =>
{
    List<Product> products = await repository.ListAsync(ct);
    return Results.Ok(products);
});

// Read/write — save via DataAccessContext (Unit of Work)
app.MapPost("/products", async (Product product, IRepository<Product> repository, CancellationToken ct) =>
{
    await repository.AddAsync(product, ct);
    await repository.DataAccessContext.SaveChangesAsync(ct);
    return Results.Created($"/products/{product.Id}", product);
});

API surface

IDataAccessContext

Method	Description
SaveChangesAsync(CancellationToken)	Persists all tracked changes. Throws NotSupportedException in read-only context.

IRepositoryReadOnly<TEntity>

Member	Description
DataAccessContext	The shared IDataAccessContext instance
GetByIdAsync<TId>(...)	Find entity by primary key
FirstOrDefaultAsync(...)	First entity, with optional predicate
SingleOrDefaultAsync(...)	Single entity, with optional predicate
ListAsync(...)	All entities, with optional predicate
CountAsync(...)	Count entities, with optional predicate
AnyAsync(...)	Check existence, with optional predicate

IRepository<TEntity> (extends IRepositoryReadOnly<TEntity>)

Method	Description
AddAsync(...)	Add a single entity
AddRangeAsync(...)	Add multiple entities
Update(...)	Mark entity as modified
UpdateRange(...)	Mark multiple entities as modified
Remove(...)	Mark entity for deletion
RemoveRange(...)	Mark multiple entities for deletion

Build

dotnet build GenericRepositories.slnx

Run sample API

dotnet run --project samples/GenericRepositories.SampleApi

Default local URL: http://localhost:5116

Test with HTTP file

Use samples/GenericRepositories.SampleApi/GenericRepositories.SampleApi.http — it contains a full CRUD flow (list, create, get by id, update, delete).