protected void btnAdd_Click(object sender, EventArgs e)
{
string k = "select s_num from snackinfo s_no=@n";//取库存数量
string n = "select s_no from snackinfo";
if (txtNo.Text==n)
{
if ( Convert .ToDouble(txtONum.Text)>Convert.ToDouble(k))
{
Response.Write("<script>alert('库存量不足!')</script>");
}
double newnum;
newnum = Convert.ToDouble(n) - Convert.ToDouble(txtONum.Text);
string sql1 = "update snackinfo set s_num=@newnum.ToString() where s_no=@n";
Class1.ExecuteNoneQuery(sql1);
Response.Write("<script> alert('更新成功啦~!'); </script> ");
}