cascading dropdownlist, second dropdown storing wrong value in database - sql

Question

I have two dropdowns Complaint_Type and Complaint_SubType. Using SqlDataSource I have populated both. SubType dropdown gets correctly populated when I choose the Type dropdown. When I select the values and press submit and check in the database both the type and subtype values are same.
.aspx code
<asp:ScriptManager ID="smDDL" runat="server"></asp:ScriptManager>
<asp:UpdatePanel ID="upDDL" runat="server">
<ContentTemplate>
<div class="form-group" style="margin-bottom: 25px;">
<asp:Label ID="lblCType" runat="server" Text="Complaint Type" data-toggle="tooltip" title="Select Complaint Type" />
<asp:RequiredFieldValidator ID="RfvDDLCompType" runat="server" ErrorMessage="Please Select Complaint Type" ControlToValidate="ddlCType" ForeColor="Red" InitialValue="0" Display="Dynamic"> *</asp:RequiredFieldValidator>
<asp:DropDownList ID="ddlCType" runat="server" CssClass="form-control" DataSourceID="SqlDataSource1" DataTextField="Comp_Type" DataValueField="Type_ID" AutoPostBack="True" OnDataBound="DDLCTypeDataBound" Style="width: 400px">
</asp:DropDownList>
<asp:SqlDataSource ID="SqlDataSource1" runat="server" ConnectionString="<%$ ConnectionStrings:ComplaintWebsiteConnectionString %>" SelectCommand="SELECT * FROM [Complaint_Type]"></asp:SqlDataSource>
</div>
<div class="form-group" style="margin-bottom: 25px;">
<asp:Label ID="lblSubType" runat="server" Text="Complaint Sub Type" data-toggle="tooltip" title="Select Complaint Sub Type" />
<asp:RequiredFieldValidator ID="rfvDDlSubType" runat="server" ErrorMessage="Please Select Complaint Sub Type" ControlToValidate="ddlSubType" ForeColor="Red" InitialValue="0" Display="Dynamic"> *</asp:RequiredFieldValidator>
<asp:DropDownList ID="ddlSubType" runat="server" CssClass="form-control" DataSourceID="SqlDataSource2" DataTextField="Comp_SubType" DataValueField="Type_ID" OnDataBound="DDLSubTypeDataBound" Style="width: inherit">
</asp:DropDownList>
<asp:SqlDataSource ID="SqlDataSource2" runat="server" ConnectionString="<%$ ConnectionStrings:ComplaintWebsiteConnectionString %>" SelectCommand="SELECT * FROM [Complaint_SubType] WHERE ([Type_ID] = #Type_ID2)">
<SelectParameters>
<asp:ControlParameter ControlID="ddlCType" Name="Type_ID2" PropertyName="SelectedValue" Type="Int32" />
</SelectParameters>
</asp:SqlDataSource>
</div>
</ContentTemplate>
</asp:UpdatePanel>
.cs code
protected void Page_Load(object sender, EventArgs e)
{
}
protected void DDLCTypeDataBound(object sender, EventArgs e)
{
ddlCType.Items.Insert(0, new ListItem("Select", "0"));
}
protected void DDLSubTypeDataBound(object sender, EventArgs e)
{
ddlSubType.Items.Insert(0, new ListItem("Select", "0"));
}
protected void btn_Reset(object Sender, EventArgs e)
{
}
protected void btnReport_Click(object Sender, EventArgs e)
{
SqlConnection con = new SqlConnection(Utils.Connection);
String query = "insert into CITIZEN_COMPLAINTS(TYPE, SUBTYPE, LOCATION, DESCRIPTION, IMAGE) values (#TYPE, #SUBTYPE, #LOCATION, #DESCRIPTION, #IMAGE)";
SqlCommand cmd = new SqlCommand(query, con);
cmd.Parameters.Add("#TYPE", SqlDbType.Int).Value = ddlCType.SelectedValue;
cmd.Parameters.Add("#SUBTYPE", SqlDbType.Int).Value = ddlSubType.SelectedValue;
cmd.Parameters.Add("#LOCATION", SqlDbType.VarChar).Value = txtLoc.Text;
cmd.Parameters.Add("#DESCRIPTION", SqlDbType.VarChar).Value = txtDesc.Text;
cmd.Parameters.Add("#IMAGE", SqlDbType.VarChar).Value = Utils.file_upload(fuImage);
try
{
con.Open();
cmd.ExecuteNonQuery();
}
catch (Exception ex)
{
//...
}
finally
{
con.Close();
}
}

Answer 1

The reason is because the DataValueField="Type_ID" is same for both drop downs in your markup for these drop downs.
For the second drop down for sub types, you should have something like DataValueField="SubType_ID".
Assuming the primary key column in Complaint_SubType table is SubType_ID, the markup below will solve your problem. Note the DataValueField in these two markups, which should be different.
Type drop down
<asp:DropDownList ID="ddlCType" runat="server" CssClass="form-control"
DataSourceID="SqlDataSource1" DataTextField="Comp_Type" DataValueField="Type_ID"
AutoPostBack="True" OnDataBound="DDLCTypeDataBound" Style="width: 400px">
</asp:DropDownList>
Sub Type drop down
<asp:DropDownList ID="ddlSubType" runat="server" CssClass="form-control"
DataSourceID="SqlDataSource2" DataTextField="Comp_SubType" DataValueField="SubType_ID"
OnDataBound="DDLSubTypeDataBound" Style="width: inherit">
</asp:DropDownList>