Question

So let’s imagine a simple IS-A relationship like this example:

create table EntityAbstract(
  IDEntityAbstract int identity primary key,
  Name nvarchar(50) not null,
)


create table OneOfConcreteEntity(
  EntityAbstract int,
  constraint PK_Image primary key (EntityAbstract),
  constraint FK_Image foreign key (EntityAbstract) references EntityAbstract(IDEntityAbstract)  
)

When i’m mapping the entities from the database should i make them individual and unique objects or should i make the concrete class extending from the abstract entity?

e.g:

  public class EntityAbstract
    {
        public int EntityAbstractID { get; set; }
        public string Name { get; set; }
        public EntityAbstract(int entityID, string name)
        {
            this.EntityAbstractID = entityID;
            this.Name = name;
        }
    }

   public class OneOfConcreatEntity : EntityAbstract
    {
        public OneOfConcreatEntity(int entityID, string name) : base(entityID, name){ }
    }

What’s the best option? considering more than one concrete entities and more complex ones.

Answer 1

There are several design patterns involving an IS-A relationship, and generally this is exactly what inheritance is for.