DDD: Enum like entities
- by Chris
Hi all,
I have the following DB model:
**Person table**
ID | Name | StateId
------------------------------
1 Joe 1
2 Peter 1
3 John 2
**State table**
ID | Desc
------------------------------
1 Working
2 Vacation
and domain model would be (simplified):
public class Person
{
public int Id { get; }
public string Name { get; set; }
public State State { get; set; }
}
public class State
{
private int id;
public string Name { get; set; }
}
The state might be used in the domain logic e.g.:
if(person.State == State.Working)
// some logic
So from my understanding, the State acts like a value object which is used for domain logic checks. But it also needs to be present in the DB model to represent a clean ERM.
So state might be extended to:
public class State
{
private int id;
public string Name { get; set; }
public static State New {get {return new State([hardCodedIdHere?], [hardCodeNameHere?]);}}
}
But using this approach the name of the state would be hardcoded into the domain.
Do you know what I mean? Is there a standard approach for such a thing? From my point of view what I am trying to do is using an object (which is persisted from the ERM design perspective) as a sort of value object within my domain. What do you think?
Question update:
Probably my question wasn't clear enough.
What I need to know is, how I would use an entity (like the State example) that is stored in a database within my domain logic. To avoid things like:
if(person.State.Id == State.Working.Id)
// some logic
or
if(person.State.Id == WORKING_ID)
// some logic
