EF is reinserting Entities

Question

I have this code

            DivisionService divService = new DivisionService();
            Division div = divService.FindById(10); 
            Counter c = new Counter(div);

            unitOfWork.CounterRepository.Add(c);
            unitOfWork.SaveChanges();

This code is supposed to add a new Counter and not to add a new Division since the division is retrieved from the database, but what happens is that it adds both. Any idea what could be the problem?

EDIT

Below is the class Counter

public class Counter : BaseCounter
{

    Division division;

    private Counter()
    {

    }

    public Counter(Division division)
    {
        this.division = division;
    }

    public Division Division
    {
        get
        {
            return division;
        }
        private set
        {
            division = value;
        }
    }

    public override string GetNumber()
    {
        return number.ToString();
    }
}

Here is also the BaseCounterRepository that the CounterRepository and CounterService wraps

public abstract class BaseCounterRepository<T> where T : BaseCounter
{

    protected MyContext context;

    public BaseCounterRepository()
    {
        this.context = new MyContext();
    }

    public BaseCounterRepository(MyContext context)
    {
        this.context = context;
    }

    public virtual T FindById(int id)
    {
        T result = default(T);

        try
        {
            result = (T)context.Set<T>().Find(id);
        }
        catch (Exception ex)
        {
            // handle execption
        }

        return result;
    }

    public virtual T Add(T obj)
    {
        try
        {
            T result = context.Set<T>().Add(obj);
            return result;
        }
        catch (Exception ex)
        {
            // handle execption
        }
    }

    public virtual void DeleteById(int id)
    {
        try
        {
            T entity = context.Set<T>().Find(id);
            context.Set<T>().Remove(entity);
        }
        catch (Exception ex)
        {
            // handle execption
        }
    }

}

If you do not want to save division, do not provide it to the counter model. One of the reason why you should keep data access related models keep separate from business layer — Fabio, Oct 03 '17 at 11:14
@MatthiasBurger that was me who posted this question, and I choose independent association based on my understanding of article number 2 in the answer. — Sisyphus, Oct 03 '17 at 11:17
@Fabio it is a matter of business requirement, I can't construct a Counter with a Division. — Sisyphus, Oct 03 '17 at 11:18

Sisyphus · Answer 1 · 2017-10-03T11:59:46.737

0

This question inspired me with the answer , it turned out that I was using different UnitOfWork (consequently DBContext) per Service class, that's why the Division from the DivisionService class looked new to the CounterService class and its DBContext and thus got reinserted.

edited Oct 03 '17 at 11:59

answered Oct 03 '17 at 11:49

Sisyphus

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EF is reinserting Entities

1 Answers1