C# Using Database column as part of the Image name

Hi

I'm trying to learn c# but from a classic asp background, I get very confused (easily)

I am trying to fetch and dispay an image. All I need from the database is the productid the rest of the url will be hard coded like this

"http://www.example.com/" + <%# MyProductid %> + ".jpg"


 <asp:Image ID="Image1" runat="server" Width="200" Height="200" ImageUrl='<%# "http://www.example.com/" + <%# MyProductid %> + ".jpg" %>' />

but that does not work.

it does work for things like title
<title><%= MyTitle %></title>

my data looks like this

public partial class _Default : System.Web.UI.Page 
{
    private string myTitle;
    protected string MyTitle
    {
        get { return myTitle; }
        set { myTitle = value; }
    }
    private string myHeading;
    protected string MyHeading
    {
        get { return myHeading; }
        set { myHeading = value; }
    }
    private string myProductinfo;
    protected string MyProductinfo
    {
        get { return myProductinfo; }
        set { myProductinfo = value; }
    }
    private string myProductid;
    protected string MyProductid
    {
        get { return myProductid; }
        set { myProductid = value; }
    }
    protected void Page_Load(object sender, EventArgs e)
    {
        String ConnStr = "";
        String SQL = "SELECT a.productname,a.productid,b.description,a.tag,a.modelnumber FROM table a join be_posts b on a.productid = b.productid WHERE a.productid ='20130'";
        SqlDataAdapter TitlesAdpt = new SqlDataAdapter(SQL, ConnStr);
        DataSet Titles = new DataSet();
        TitlesAdpt.Fill(Titles);
        DataRow dr = Titles.Tables[0].Rows[0];
        dr["productname"].ToString();
        MyTitle = dr["productname"].ToString();
        myHeading = dr["productname"].ToString();
        myProductinfo = dr["description"].ToString();
        myProductid = dr["productid"].ToString();
        
    }
}

please can someone show me an example of how to do this properly?