Best way to save type of class in database?

Question

What is a good way to denote \"type\" in database?

I have a base class Action which is inherited by numerous child classes. Actio

Answer 1

I ended up using option 2, but with less clutter of attributes. Something like this:

public abstract class Action
{
    public enum Kind 
    {
        ControlAction = 1, 

        UpdateAction = 2, 

        etc 
    }

    public abstract Kind ActionType { get; }
}

public class ControlAction : Action { public override Kind ActionType { get { return Kind.ControlAction; } } }
public class UpdateAction : Action { public override Kind ActionType { get { return Kind.UpdateAction; } } }

The biggest advantage for this is that (even if it meant more typing), it enforces a numeric value to be associated with a class type.

Now class to int is just:

var value = (int)instance.ActionType;

Very fast.

But to convert int to class instance (or class type), I will have to create an instance of each sub action types, and compare its ActionType property to match the input int value. This is going to be slow. But I can cache somethings and make it faster. Something like:

static readonly Dictionary actionTypes = 
   GetDefaultInstanceOfAllActions().ToDictionary(x => x.ActionType, x => x.GetType());
public static Action ToAction(this Action.Kind value)
{
    return (Action)Activator.CreateInstance(actionTypes[value]);
}

The GetDefaultInstanceOfAllActions does some reflection (once) to get all types of actions (I use something like this answer for that). I can even make the make the instantiation faster by going the expression route.

The benefits:

1. Less hassle when creating a new class (no attributes).

2. Enforces an int to be tied to a class type.

3. Moderately fast with adequate caching.