DataRepositoryBase T, U

public abstract class DataRepositoryBase<T, U> : IDataRepository<T>
    where T : class, IIdentifiableEntity, new()
    where U : DbContext, new()
{
    protected abstract T AddEntity(U entityContext, T entity);

    protected abstract T UpdateEntity(U entityContext, T entity);

    protected abstract IEnumerable<T> GetEntities(U entityContext);

    protected abstract T GetEntity(U entityContext, int id);

    public T Add(T entity)
    {
        using (U entityContext = new U())
        {
            T addedEntity = AddEntity(entityContext, entity);
            entityContext.SaveChanges();
            return addedEntity;
        }
    }

    public void Remove(T entity)
    {
        using (U entityContext = new U())
        {
            entityContext.Entry<T>(entity).State = EntityState.Deleted;
            entityContext.SaveChanges();
        }
    }

    public void Remove(int id)
    {
        using (U entityContext = new U())
        {
            T entity = GetEntity(entityContext, id);
            entityContext.Entry<T>(entity).State = EntityState.Deleted;
            entityContext.SaveChanges();
        }
    }

    public T Update(T entity)
    {
        using (U entityContext = new U())
        {
            T existingEntity = UpdateEntity(entityContext, entity);

            SimpleMapper.PropertyMap(entity, existingEntity);

            entityContext.SaveChanges();
            return existingEntity;
        }
    }

    public IEnumerable<T> Get()
    {
        using (U entityContext = new U())
            return (GetEntities(entityContext)).ToArray().ToList();
    }

    public T Get(int id)
    {
        using (U entityContext = new U())
            return GetEntity(entityContext, id);
    }
}