Question

此查询查找库存可用性，打印出的标签看起来像..

{
   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 = = 0，我怎么能弹出一个消息框？

的更新 的

好的，我会解释我要做的事情

我有一个UPDATE查询，每次点击一个按钮，它会将股票减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，则会弹出一条消息或警告，说明选择缺货。

Answer 1

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

不确定是否能回答你的问题

如果query = = 0，则显示消息框

1 个答案: