ASP.NET

<dxwgv:GridViewDataHyperLinkColumn Name="colProject" FieldName="website_project_name" Caption="Project" PropertiesHyperLinkEdit-NavigateUrlFormatString='project.aspx?id=<%# Eval("website_project_id") %>' />

 private void Update()
    {


      
        string cmd = @"UPDATE EXAMEN set NOTE= CASE 
WHEN CODE_MATIERE = '1' and @note1 =99  then '0'  
when CODE_MATIERE = '1' and @note1 <>99  then @note1  
        WHEN CODE_MATIERE = '2' and @note2 ='99'  then '0'  
when CODE_MATIERE = '2' and @note2 <>99  then @note2 END, PRESENCE=
CASE WHEN CODE_MATIERE = '1' and @note1 =99 then 'TRUE' 
when CODE_MATIERE = '2' and @note2 ='99'  then 'TRUE'  else 'FALSE'

end
WHERE NUM_INSCRIPTION = @num;";

       
        float note1, note2;
        string num;
        SqlCommand myCommand;
        SqlParameter param1, param2, param3;

        using (SqlConnection myConnection = new SqlConnection(ConnectionString))
        {
            myConnection.Open();

            foreach (GridViewRow row in GridView1.Rows)
            {
                note1 = float.Parse(((TextBox)row.FindControl("tmoy1")).Text);
                note2 = float.Parse(((TextBox)row.FindControl("tmoy4")).Text);
                num = ((Label)row.FindControl("lblUserID1")).Text;
               
                myCommand = new SqlCommand(cmd, myConnection);
           
                param1 = new SqlParameter("num", SqlDbType.VarChar, 4);
                param1.Value = num;
                myCommand.Parameters.Add(param1);

                param2 = new SqlParameter("note1", SqlDbType.Float, 2);
                param2.Value = note1;
                myCommand.Parameters.Add(param2);

                param3 = new SqlParameter("note2", SqlDbType.Float, 2);
                param3.Value = note2;
                myCommand.Parameters.Add(param3);
               
               myCommand.ExecuteNonQuery();
              
            }        

        }  myConnection.Close();

    }