namespace EF_Sample07.DataLayer.Context
{
    public interface IUnitOfWork
    {
        IDbSet<TEntity> Set<TEntity>() where TEntity : class;
        int SaveAllChanges();
        void MarkAsChanged<TEntity>(TEntity entity) where TEntity : class;
    }
}

namespace EF_Sample07.DataLayer.Context
{
    public class Sample07Context : DbContext, IUnitOfWork
    {
        public DbSet<Category> Categories { set; get; }
        public DbSet<Product> Products { set; get; }

        public new IDbSet<TEntity> Set<TEntity>() where TEntity : class
        {
            return base.Set<TEntity>();
        }

        public int SaveAllChanges()
        {
            return base.SaveChanges();
        }

        public void MarkAsChanged<TEntity>(TEntity entity) where TEntity : class
        {
            base.Entry<TEntity>(entity).State = EntityState.Modified;
        }
    }
}