Using a dropdown box in a GridView - How do I update the record with the dd's value?

Lee Dumond · March 13th, 2009, 10:45 AM

Yes, obviously I am talking aonly about binding in Edit mode here.

I know my solution is correct. I may have not have given you the exactly right column name to Bind to. It is confusing because you haven't provided the schema (column names) of your tables here, so I'm just guessing at that.

You might have to use Bind("Name") or something else, depending on what your column names are.

I am going to post the known working example I came up with to prove this concept. Maybe you can take it from there.

Lee Dumond · March 13th, 2009, 11:04 AM

HTML Code:

<%@ Page Language="C#" %>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<script runat="server">
</script>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
   <title>GridView DroopDown Edit</title>
</head>
<body>
   <form id="form1" runat="server">
      <asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False"
         DataKeyNames="ProductID" DataSourceID="SqlDataSource1">
         <Columns>
            <asp:CommandField ShowEditButton="True" />
            <asp:BoundField DataField="ProductID" HeaderText="ProductID"
               InsertVisible="False" ReadOnly="True" SortExpression="ProductID" />
            <asp:TemplateField HeaderText="Category">
               <EditItemTemplate>
                  <asp:DropDownList ID="DropDownList1" runat="server" DataSourceID="SqlDataSource2"
                     DataTextField="CategoryName" DataValueField="CategoryID" SelectedValue='<%# Bind("CategoryID") %>'>
                  </asp:DropDownList>
                  <asp:SqlDataSource ID="SqlDataSource2" runat="server" ConnectionString="<%$ ConnectionStrings:NorthwindConnectionString %>"
                     SelectCommand="SELECT [CategoryID], [CategoryName] FROM [Categories]">
                  </asp:SqlDataSource>
               </EditItemTemplate>
               <ItemTemplate>
                  <asp:Literal ID="Literal1" runat="server" Text='<%# Eval("CategoryName") %>' />
               </ItemTemplate>
            </asp:TemplateField>
            <asp:BoundField DataField="ProductName" HeaderText="ProductName"
               SortExpression="ProductName" />
         </Columns>
      </asp:GridView>
      <asp:SqlDataSource ID="SqlDataSource1" runat="server" ConflictDetection="CompareAllValues"
         ConnectionString="<%$ ConnectionStrings:NorthwindConnectionString %>"
         OldValuesParameterFormatString="original_{0}"
         SelectCommand="SELECT Products.ProductID, Products.ProductName, Products.CategoryID, Categories.CategoryName FROM Categories INNER JOIN Products ON Categories.CategoryID = Products.CategoryID"
         DeleteCommand="DELETE FROM [Products] WHERE [ProductID] = @original_ProductID AND (([CategoryID] = @original_CategoryID) OR ([CategoryID] IS NULL AND @original_CategoryID IS NULL)) AND [ProductName] = @original_ProductName"
         InsertCommand="INSERT INTO [Products] ([CategoryID], [ProductName]) VALUES (@CategoryID, @ProductName)"
         UpdateCommand="UPDATE [Products] SET [CategoryID] = @CategoryID, [ProductName] = @ProductName WHERE [ProductID] = @original_ProductID AND (([CategoryID] = @original_CategoryID) OR ([CategoryID] IS NULL AND @original_CategoryID IS NULL)) AND [ProductName] = @original_ProductName">
         <DeleteParameters>
            <asp:Parameter Name="original_ProductID" Type="Int32" />
            <asp:Parameter Name="original_CategoryID" Type="Int32" />
            <asp:Parameter Name="original_ProductName" Type="String" />
         </DeleteParameters>
         <UpdateParameters>
            <asp:Parameter Name="CategoryID" Type="Int32" />
            <asp:Parameter Name="ProductName" Type="String" />
            <asp:Parameter Name="original_ProductID" Type="Int32" />
            <asp:Parameter Name="original_CategoryID" Type="Int32" />
            <asp:Parameter Name="original_ProductName" Type="String" />
         </UpdateParameters>
         <InsertParameters>
            <asp:Parameter Name="CategoryID" Type="Int32" />
            <asp:Parameter Name="ProductName" Type="String" />
         </InsertParameters>
      </asp:SqlDataSource>
   </form>
</body>
</html>

RushNP774 · March 13th, 2009, 12:53 PM

Sorry for the misunderstanding Lee. It was late and I wasn't thinking clearly. Thanks for your code snippet. I'll play around with it until I get it to work, and will let you know what I was doing wrong. Thanks again!

Lee Dumond · March 13th, 2009, 01:06 PM

If you have the Northwind database and can connect to it, and define "NorthwindConnectionString" as the connection string name, then you should be able to paste this straight into an .aspx file and run it.

RushNP774 · March 15th, 2009, 02:57 AM

Lee, I played around with it for a long time and got everything to work, until I restarted my project... I keep getting this error (and it happened before I got it work as well. I just don't remember what I changed):

DataBinding: 'System.Data.DataRowView' does not contain a property with the name 'CategoryName'

When I get to this line:

Code:

<asp:Literal ID="Literal1" runat="server" Text='<%# Eval("CategoryName") %>'/>

"CategoryName" is the field in my [Categories] table that holds the description of the category. I have Categories.CategoryName pulling correctly from my SelectStatement, so it seems odd that the Eval statement can't find it.

The site runs fine when I replace the Eval statement with ActivityCategoryID from my [Activities] table, but the GridView just shows the ID and not the name.

Any ideas?