开关大小写与下拉列表可用性/面板可见性冲突

我使用的是 C# ASP.NET，我有一个提交页面，当您单击添加产品链接时，它会打开一个弹出的"添加产品"页面，其中包含可以添加到提交中的产品下拉列表。业务规则规定每个产品在任何提交中只能有一个实例，因此我运行了两个单独的 switch case 语句，一个用于在弹出窗口中选择项目后从下拉列表中删除项目，另一个用于查询数据库以确定是否有任何产品已经与提交关联， 如果是这样，也从下拉列表中删除这些选项。用户从下拉列表中选择项目后，该产品的面板将可见以供用户输入。

这两个开关盒

的功能是，它们消除了不应该可用的项目，但是由于我放入了查询的开关盒，因此面板在选择后不再可见。当我删除查询的开关案例时，面板在选择时确实变得可见，但已经与提交关联的产品仍然在下拉列表中可用。

我知道这里有冲突的某个地方，但我对它是什么感到不安，因为这是我第一次尝试编程。代码如下。请忽略查询本身;这是一个非主动训练项目，我的处理程序禁止参数化，因为他希望我先学习基础知识。我了解注入漏洞。

    public partial class AddProduct : System.Web.UI.Page
{

protected void BtnAddProduct_Click(object sender, EventArgs e)
{
    switch (DdlProductList.SelectedValue)
    {
        case "1":
            PanelEpl.Visible = true;
            DdlProductList.Items.Remove(DdlProductList.SelectedItem);
            break;
        case "2":
            PanelProf.Visible = true;
            DdlProductList.Items.Remove(DdlProductList.SelectedItem);
            break;
        case "3":
            PanelCrime.Visible = true;
            DdlProductList.Items.Remove(DdlProductList.SelectedItem);
            break;
        case "4":
            PanelFid.Visible = true;
            DdlProductList.Items.Remove(DdlProductList.SelectedItem);
            break;
        case "5":
            PanelNotProf.Visible = true;
            DdlProductList.Items.Remove(DdlProductList.SelectedItem);
            break;
        case "6":
            PanelPriv.Visible = true;
            DdlProductList.Items.Remove(DdlProductList.SelectedItem);
            break;
        case "7":
            PanelPub.Visible = true;
            DdlProductList.Items.Remove(DdlProductList.SelectedItem);
            break;
        default:
                break;
        }
    }
    protected void Page_Load(object sender, EventArgs e)
    {
        string x = Request.QueryString["SubId"];
        string connectionString = System.Configuration.ConfigurationManager.ConnectionStrings["MyConnectionString"].ConnectionString;
        string displayQuery = "SELECT CustName, CustAdd, CustCity, CustState, CustZip FROM Customer WHERE SubId =" + x;
        string broQuery = "SELECT EntityType FROM Broker WHERE SubId =" + x;
        string ddlQuery = "SELECT ProductId FROM SubmissionProducts WHERE SubmissionId =" + x;
        using (SqlConnection displayConn = new SqlConnection(connectionString))
        {
            displayConn.Open();
            SqlCommand DlistCmd = new SqlCommand(ddlQuery, displayConn);
            using (SqlDataReader Ddldr = DlistCmd.ExecuteReader())
            {
                while (Ddldr.Read())
                {
                    switch (Ddldr.GetInt32(0))
                    {
                        case 1:
                            DdlProductList.Items.RemoveAt(1);
                            break;
                        case 2:
                            DdlProductList.Items.RemoveAt(2);
                            break;
                        case 3:
                            DdlProductList.Items.RemoveAt(3);
                            break;
                        case 4:
                            DdlProductList.Items.RemoveAt(4);
                            break;
                        case 5:
                            DdlProductList.Items.RemoveAt(5);
                            break;
                        case 6:
                            DdlProductList.Items.RemoveAt(6);
                            break;
                        case 7:
                            DdlProductList.Items.RemoveAt(7);
                            break;
                        default:
                            break;
                    }
                }
            }

protected void Page_Load(object sender, EventArgs e)
{
 If(!IsPostBack)
 {
    string x = Request.QueryString["SubId"];
    string connectionString = System.Configuration.ConfigurationManager.ConnectionStrings["MyConnectionString"].ConnectionString;
    string displayQuery = "SELECT CustName, CustAdd, CustCity, CustState, CustZip FROM Customer WHERE SubId =" + x;
    string broQuery = "SELECT EntityType FROM Broker WHERE SubId =" + x;
    string ddlQuery = "SELECT ProductId FROM SubmissionProducts WHERE SubmissionId =" + x;
    using (SqlConnection displayConn = new SqlConnection(connectionString))
    {
        displayConn.Open();
        SqlCommand DlistCmd = new SqlCommand(ddlQuery, displayConn);
        using (SqlDataReader Ddldr = DlistCmd.ExecuteReader())
        {
            while (Ddldr.Read())
            {
                switch (Ddldr.GetInt32(0))
                {
                    case 1:
                        DdlProductList.Items.RemoveAt(1);
                        break;
                    case 2:
                        DdlProductList.Items.RemoveAt(2);
                        break;
                    case 3:
                        DdlProductList.Items.RemoveAt(3);
                        break;
                    case 4:
                        DdlProductList.Items.RemoveAt(4);
                        break;
                    case 5:
                        DdlProductList.Items.RemoveAt(5);
                        break;
                    case 6:
                        DdlProductList.Items.RemoveAt(6);
                        break;
                    case 7:
                        DdlProductList.Items.RemoveAt(7);
                        break;
                    default:
                        break;
                }
            }
        }