c# - 如果查询 = 到 0，则显示消息框

Question

此查询查找库存可用性，标签打印输出如下所示..

{
   string selection_price = DdPetPist.SelectedValue;
   string selection_stock = DdPetPist.SelectedValue;
   string petPrice = string.Empty;
   string available = string.Empty;
   {
      MySqlCommand cd_price = new MySqlCommand(String.Format("SELECT Price FROM Animals WHERE Specie ='{1}' and Country ='{0}'", ddlcountry.SelectedItem.ToString().Trim(), selection_price), cs);
      MySqlCommand cd_available = new MySqlCommand(String.Format("SELECT Stock FROM Animals WHERE Specie ='{1}' and Country ='{0}'", ddlcountry.SelectedItem.ToString().Trim(), selection_stock), cs);

      cs.Open();
      petPrice = Convert.ToString(cd_price.ExecuteScalar());
      available = Convert.ToString(cd_available.ExecuteScalar());
      cs.Close();
   }
   PetPrice.Text = String.Format("Minimum Donation For A {0}  Is £{1}.", selection_price, petPrice);
   Availble.Text = String.Format("{0}'s Avalible {1} In Your Country.", selection_stock, available);
}

如果stock，如何弹出消息框= 到 0 吗？

更新

好的，我会解释一下我想要做什么

我有一个UPDATE每次单击按钮时，查询都会将股票减 1。查询如下:

var myquery = string.Format("UPDATE Animals SET Stock = Stock - 1 WHERE Specie ='{1}'
and Country ='{0}' and Stock >0", ddlcountry.SelectedItem.ToString().Trim(), 
selection_price);

现在我想要的是如果 stock = = 0 会弹出一条消息或警报，提示所选产品缺货。

Answer 1

if(available == 0)
{
   Messagebox.show("stock is equal to zero");
}

不确定这是否能回答您的问题