Hi folks,
I'm new to .Net website programming and have a simple question. I'm just
trying to create a page that has 3 drop down menus and a submit button. The
3 drop down menus are controls that are included on a web form. The 'code
behind' page generates the drop down menus. After the user hits submit I
have some code on the web form that does a sql query and prints the records
into a data form. Here's the code:
<%@Import NameSpace="System.Data" %>
<%@Import NameSpace="System.Data.SqlClient" %>
<%@ Register Tagprefix="CLO" TagName="ClassProgressSubjectDropDown"
src="SubjectDropDown.ascx" %>
<%@ Register Tagprefix="CLO" TagName="ClassProgressClassDropDown"
src="ClassDropDown.ascx" %>
<%@ Register Tagprefix="CLO" TagName="ClassProgressScoreFilter"
src="ScoreFilter.ascx" %>
<%@ OutputCache Duration="20" VaryByParam="*" %>
<%@ Page Language="VB" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML>
<HEAD>
<title>Class Progress Report</title>
<script runat="server">
Sub btnSubmit_Click(sender as object, e as eventargs)
Dim myConnection As SqlConnection
Dim myCommand As SqlCommand
Dim myReader As SqlDataReader
Dim SQL As String
Dim ConnStr As String
ConnStr = "server=CHILDU-LAB1;database=TLO;UID=TLO;PWD=tlo"
SQL = "SELECT " & _
"Class_ID, Test_ID, Content_Standard_ID,
Grade_Cd, Subject_Cd, Test_title, Content_Standard_Description,
Display_Order, " & _
"Num_students_taken, Num_Mastered,
Num_Not_Mastered " & _
"FROM " & _
"Class_Report "& _
"WHERE " & _
"class_id = 1 " & _
"AND " & _
"subject_cd = '" &
Subject.SelectedIndex.Value & "' " & _
"ORDER BY " & _
"grade_cd, display_order"
Try
myConnection = New SqlConnection(ConnStr)
myConnection.Open()
myCommand = New SqlCommand(SQL, myConnection)
myReader = myCommand.ExecuteReader()
dgrResult.DataSource = myReader
dgrResult.DataBind()
Catch ex As Exception
Throw New Exception(ex.ToString())
Finally
End Try
End Sub
</script>
<meta content="Microsoft Visual Studio.NET 7.0"
name="GENERATOR">
<meta content="Visual Basic 7.0" name="CODE_LANGUAGE">
<meta content="JavaScript" name="vs_defaultClientScript">
<meta
content="http://schemas.microsoft.com/intellisense/ie5"
name="vs_targetSchema">
</HEAD>
<body MS_POSITIONING="GridLayout">
<P><br>
<br>
<IMG src="header.bmp"></P>
<P align="center">Class Progress Report</P>
<form id="frmClassProgress" action="WebForm2.aspx"
method="post" runat="server">
<CLO:CLASSPROGRESSSUBJECTDROPDOWN
id="ClassProgressSubjectDropDown"
runat="server"></CLO:CLASSPROGRESSSUBJECTDROPDOWN>
<CLO:CLASSPROGRESSCLASSDROPDOWN
id="ClassProgressClassDropDown"
runat="server"></CLO:CLASSPROGRESSCLASSDROPDOWN>
<CLO:CLASSPROGRESSSCOREFILTER
id="ClassProgressScoreFilter" runat="server"></CLO:CLASSPROGRESSSCOREFILTER>
<asp:button id="btnSubmit" style="Z-INDEX: 101;
LEFT: 360px; POSITION: absolute; TOP: 280px" onclick="btnSubmit_Click"
Runat="server" Text="Submit"></asp:button>
</form>
<asp:datagrid id="dgrResult" style="Z-INDEX: 102; LEFT:
18px; POSITION: absolute; TOP: 355px" Runat="server"></asp:datagrid>
</body>
</HTML>
The part it is bombing on is where I try to reference
Subject.SelectedIndex.Value to dynamically create the SQL statement.
Here is the component code:
<%@ Control Language="vb" Codebehind="SubjectDropDown.ascx.vb"
Inherits="WebApplication1.SubjectDropDown" AutoEventWireup="false"%>
<asp:Label id="Label1" Width="161px" runat="server">Subject</asp:Label>
<asp:DropDownList id="Subject" DataTextField="description"
DataValueField="subject_cd" runat="server">
</asp:DropDownList>
The codebehind stuff works because if i put a static value in the SQL
statement the page works. Any help would be greatly appreciated. If the
error page that I get is needed for help on debugging I will post it, but
the error message makes no sense to me.
thanks in advance,
Greg
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