public void Save(ProductCategoryItem item)
{
var errors = item.GetValidationErrors();
errors.ThrowIfHasErrors();
var category = item.Id == 0 ? Db.CreateAndAdd <tblProductCategory>() : Db.Set <tblProductCategory>().Single(x => x.Id == item.Id);
category.Name = item.Name;
category.ParentCategoryId = item.ParentCategoryId;
Db.SaveChanges();
item.Id = category.Id;
}