AspnetCore.Data 3.1.1

Startup.cs

public void ConfigureServices(IServiceCollection services)
{
    //other configurations...

    services.AddScoped<IUnityContainer, UnityContainer>();

    var container = services.BuildServiceProvider().GetService<IUnityContainer>();

    container.RegisterType<ICategoryRepository, CategoryRepository>();
    container.RegisterType<IOrderRepository, OrderRepository>();
    container.RegisterType<ICustomerRepository, CustomerRepository>();

    services.AddScoped<IUnitOfWork>(o => new UnitOfWork<NORTHWNDContext>(container));


}

HomeController.cs

public class BaseController : Controller
{
    public IUnitOfWork _uow;

    public BaseController(IUnitOfWork uow)
    {
        _uow = uow;
    }
}

public class HomeController : BaseController
{
    private IOrderRepository _ordersRepo;
    private ICustomerRepository _custRepo;
    private ICategoryRepository _categRepo;

    public HomeController(IUnitOfWork uow) : base(uow)
    {
        _ordersRepo = uow.Get<IOrderRepository>();
        _custRepo = uow.Get<ICustomerRepository>();
        _categRepo = uow.Get<ICategoryRepository>();
    }
	
	
	public void Demo()
	{
		//add
		_categRepo.Add(new Categories { CategoryName = "test", Description = "none" });

		//get
		var cust = _custRepo.Get(c => c.CustomerId == "ALFKI");

		//update
		cust.Address = "Test address";
		_custRepo.Update(cust);

		//delete
		var categ = _categRepo.Get(c => c.CategoryId == 2);
		_categRepo.Remove(categ);

		_uow.Commit();
	}
	
	
	public void Demo2()
	{
		var categoreis = _categRepo.GetCategories();

		var orders = _ordersRepo.GetOrders();

		var cusomters = _custRepo.GetCustomers();

		var customer = _custRepo.GetCustomer("ALFKI");
	}		
}

Repositories

public interface ICategoryRepository : IDataRepository<Categories>
{
    IEnumerable<Categories> GetCategories();
}
public class CategoryRepository : DataRepository<Categories>, ICategoryRepository
{
    public CategoryRepository(DbContext dbContext) : base(dbContext)
    {
    }

    public IEnumerable<Categories> GetCategories()
    {
        return base.SqlQuery<Categories>("select * from categories").ToList();
    }
}

public interface IOrderRepository : IDataRepository<Orders>
{
    IEnumerable<Orders> GetOrders();
}
public class OrderRepository : DataRepository<Orders>, IOrderRepository
{
    public OrderRepository(DbContext dbContext) : base(dbContext)
    {
    }

    public IEnumerable<Orders> GetOrders()
    {
        return base.SqlQuery<Orders>("select * from Orders").ToList();
    }
}

public interface ICustomerRepository : IDataRepository<Customers>
{
    IEnumerable<Customers> GetCustomers();
    Customers GetCustomer(string customerId);
}
public class CustomerRepository : DataRepository<Customers>, ICustomerRepository
{
    public CustomerRepository(DbContext dbContext) : base(dbContext)
    {
    }

    public Customers GetCustomer(string customerId)
    {
        var (cust,outParams) = base.SqlQuery2<Customers>("spGetCustomersById", true, new { CustomerId = customerId }, new { TotalRows = 0 });

        var count = outParams.Get<int>("TotalRows");

        return cust.FirstOrDefault();
    }

    public IEnumerable<Customers> GetCustomers()
    {
        return base.SqlQuery<Customers>("spGetCustomers",true).ToList();
    }
}	

SQL scripts sample

//
create proc spGetCustomersById
@CustomerId varchar(20),
@TotalRows int out
as
begin
	select * from Customers where CustomerID = @CustomerId
	select @TotalRows = count(1) from Customers where CustomerID = @CustomerId
end

//
create proc spGetCustomers
as
begin
	select * from Customers
end