Can you give an example where standard CRUD operations are combined with additional custom business logic?

Example of combining standard CRUD operations with additional business logic in C#:

public class OrderService
{
    private readonly IOrderRepository _repository;

    public OrderService(IOrderRepository repository)
    {
        _repository = repository;
    }

    public void CreateOrder(Order order)
    {
        // Business logic: check product availability
        if (!IsProductAvailable(order.ProductId, order.Quantity))
            throw new InvalidOperationException("Product not available in the required quantity");

        // Standard create operation
        _repository.Add(order);

        // Additional logic: notify user
        NotifyUser(order.UserId, "Your order has been created");
    }

    // Other CRUD methods with business logic
}

Here, creating an order is a CRUD operation, but before saving, business rules are checked, and after, a notification is sent.