IEntity where Key/ID type unknown

Question

I've been exploring the use of data repositories in C# as I'm working on my first "big" application in quite some time (and my first with C#). Particularly I used some information from http://web.archive.org/web/20150404154203/https://www.remondo.net/repository-pattern-example-csharp/ as well as the MSDN and stackoverflow.

I seem to have gotten stuck at something that I think may be quite simple, but I've tried googling, etc. and either it's more complex than I thought, or I'm using the wrong terminology.

Basically, when I am defining my IEntity interface as something like this:

namespace Test.Database
{
    public interface IEntity
    {
         int KeyValue { get; set; }
    }
}

That works great for most things, but this project is using an existing, nasty database (hence why I'm trying to abstract my business logic and other dev's future business logic as far as possible from the DB) where not all keys are an integer. There are keys that are character, integers, doubles, etc. Is there a way where I can make the interface's key property, type-agnostic? Or am I looking at this whole thing the wrong way?

Answer 1

you could use Generics to make it strongly typed based on your situation. Ex.,

namespace Test.Database
{
    public interface IEntity<T>
    {
         T KeyValue { get; set; }
    }
}