public bool delete(Product product)
 {
     using (MyDemoEntities mde = new MyDemoEntities())
     {
         try
         {
             int id = Convert.ToInt32(product.Id);
             ProductEntity pe = mde.ProductEntities.Single(p => p.Id == id);
             mde.ProductEntities.Remove(pe);
             mde.SaveChanges();
             return true;
         }
         catch
         {
             return false;
         }
     }
 }
 public bool edit(Product product)
 {
     using (MyDemoEntities mde = new MyDemoEntities())
     {
         try
         {
             int id = Convert.ToInt32(product.Id);
             ProductEntity pe = mde.ProductEntities.Single(p => p.Id == id);
             pe.Name = product.Name;
             pe.Price = product.Price;
             pe.Quantity = product.Quantity;
             mde.SaveChanges();
             return true;
         }
         catch
         {
             return false;
         }
     }
 }
 public bool create(Product product)
 {
     using (MyDemoEntities mde = new MyDemoEntities())
     {
         try
         {
             ProductEntity pe = new ProductEntity();
             pe.Name = product.Name;
             pe.Price = product.Price;
             pe.Quantity = product.Quantity;
             mde.ProductEntities.Add(pe);
             mde.SaveChanges();
             return true;
         }
         catch
         {
             return false;
         }
     }
 }