public T Update<T>(T entity) where T : ModelBase        {            var set = this.Set<T>();            set.Attach(entity);            foreach (System.Reflection.PropertyInfo p in entity.GetType().GetProperties())            {                if (p.GetValue(entity) != null)                {                    this.Entry<T>(entity).Property(p.Name).IsModified = true;                }            }            this.SaveChanges();            return entity;        }

 foreach (PropertyInfo p in codeRuleEntity.GetType().GetProperties())  {    if (p.GetValue(codeRuleEntity) == null)     {          db.Entry(codeRuleEntity).Property(p.Name).IsModified = true;     }  }db.Entry(codeRuleEntity).State = EntityState.Modified;