How to evade implementing full CRUD for each class in business data layer in c#?

Question

So I'm making a business data layer in my app so I obviously need API for accessing my data.

How do I evade choosing between:

Implementing ICreatable, IReadable, IUpdatable, IDeletable which are practically identical for each class which makes me write the same code a lot
Extending an existing generic data class which has all 4 CRUD which I do not like since I want some data to be read only

What I'd really like is multiple inheritance so that I can simply extend with Creatable, Removable, Updatable or Removable abstract classes when I need em

I was thinking about making abstract CRUDable and Readable classes which seems to be the least amount of repetitive coding while avoiding multiple inheritance and maintenance issues

You don't need multiple inheritance, just inheritance. Have a read-only class, then an update-able class which inherits from read-only and a delete-able class which inherits from update-able. (it's unlikely you *need* write-only DB and delete tends to imply update). — freedomn-m, Jul 28 '15 at 08:16

score 1 · Answer 1 · answered Jul 28 '15 at 07:54

If I understand your question correctly, I think what you are looking for is to make use of composition. For example:

public class OrderRepository<Order> : ICreateable<Order>, IReadable<Order>, IUpdateable<Order>, IDeleteable<Order>
{
    private ICreateable<Order> _createable;
    private IReadable<Order> _readable;
    private IUpdateable<Order> _updateable;
    private IDeleteable<Order> _deleable;

    public void Add(Order item)
    {
        _createable.Add(item);
    }

    public Order GetById(int id)
    {
        return _readable.GetById(id);
    }
}

public class Creatable<T> : ICreateable<T>
{
    public void Add(T item)
    {
        //Add to entity framework?
    }
}

public class Readable<T> : IReadable<T>
{
    public T GetById(int id)
    {
        //Get from entity framework?
    }
}

This way you only write the generic components once, and chose which repositories support them via implementing their corresponding interface

Could you please provide example class which only implement IReadable? — ditoslav, Jul 28 '15 at 09:13
Well you just don't implement the IReadable interface, and don't have a field to store the Readable — David Masters, Jul 28 '15 at 10:11
I must admit I can't understand what you just said xD. I'll do some more reading on this. Thanks — ditoslav, Jul 28 '15 at 11:49

score 0 · Answer 2 · answered Jul 28 '15 at 07:51

0

You can use Unit-Of-Work, to have a practical repository for all your classes. Take a look at my implementation here

If you want to add more models, you simply have to put 1 line in IUowData interface, and one small method in UowData class

I hope this helps.

answered Jul 28 '15 at 07:51

stann1

576
3
11

But the UOW pattern is already implemented into entity framework which I'm using on my data access layer so I would have 2 UOW layers, right? – ditoslav Jul 28 '15 at 07:53

How to evade implementing full CRUD for each class in business data layer in c#?

2 Answers2