Select value in template drpdown and fill bound column

[Felice]

I have a dropdownlist in template which is bound to a the db:

<telerik:RadDropDownList ID="RadDropDownList1" runat="server"  DataSourceID="SqlDataSource2"
          DataTextField="Pnum"  DataValueField="Pnum" SelectedValue='<%#Bind("Pnum") %>'>
         </telerik:RadDropDownList>

Then  I have a bound column "Project" that I would like to be automatically filled in when a value in the dropdown is selected based on a query:
Select Project from Pnum where Project = dropdown selected value, and save it.

How can I achieve that?
Your help will be appreciated.
Thanks,
Felice

[Princy]

Hi Felice,

I guess you have the RadDropDownList  in the ItemTemplate and you want to change a BoundColumn value based on DropDown selection. Please take a look at the following code snippet.

ASPX:

<telerik:GridTemplateColumn>
    <ItemTemplate>
        <telerik:RadDropDownList ID="RadDropDownList1" runat="server" DataSourceID="SqlDataSource2"
            DataTextField="Pnum" DataValueField="Pnum" SelectedValue='<%#Bind("Pnum") %>'
            OnSelectedIndexChanged="RadDropDownList1_SelectedIndexChanged" AutoPostBack="true">
        </telerik:RadDropDownList>
    </ItemTemplate>
</telerik:GridTemplateColumn>

C#:

protected void RadDropDownList1_SelectedIndexChanged(object sender, DropDownListEventArgs e)
{
 RadDropDownList droplist = sender as RadDropDownList;
 GridDataItem item = droplist.NamingContainer as GridDataItem;
 DataTable dt=GetDataTable("SELECT Project FROM TableName WHERE Project='"+droplist.SelectedItem.Text+"'");
 string value = dt.Rows[0]["Project"].ToString();
 item["Project"].Text = value;
}

Thanks,
Princy

[Felice]

Hi Princy,
thanks for your support. This is what I did but I am getting an error:

aspx (please note that this is in a form template:

<telerik:RadDropDownList ID="RadDropDownList1" runat="server" DefaultMessage="Please select a project" DataSourceID="SqlDataSource2" DataTextField="Pnum" DataValueField="Pnum" SelectedValue='<%#Bind("Pnum") %>' Skin="Outlook" OnSelectedIndexChanged="RadDropDownList1_SelectedIndexChanged" AutoPostBack="true">
</telerik:RadDropDownList>

this is my column:

<telerik:GridBoundColumn DataField="Project" FilterControlAltText="Filter Project_column column" HeaderText="Project" UniqueName="Project">
 <ColumnValidationSettings>
<ModelErrorMessage Text="" />
</ColumnValidationSettings>
 <HeaderStyle Width="120px" />
</telerik:GridBoundColumn>

c#:

protected void RadDropDownList1_SelectedIndexChanged(object sender, DropDownListEventArgs e)
        {
         RadDropDownList droplist = sender as RadDropDownList;
         GridDataItem item = droplist.NamingContainer as GridDataItem;
         DataTable dt = GetDataTable("SELECT Project FROM Pnum WHERE Project='"+droplist.SelectedItem.Text+"'");
         string value = dt.Rows[0]["Project"].ToString();
         item["Project"].Text = value;

        }

        public DataTable GetDataTable(string query)
        {
            SqlConnection conn = new SqlConnection(System.Configuration.ConfigurationManager.ConnectionStrings["WTAConnectionString"].ConnectionString);
            conn.Open();
            SqlCommand cmd = new SqlCommand(query, conn);
            DataTable dt = new DataTable();
            dt.Load(cmd.ExecuteReader());
            return dt;
        }

I get the error " System.IndexOutOfRangeException: No rows at position 0"
on this line:   "string value = dt.Rows[0]["Project"].ToString();"

[Felice]

Hi Princy,

I sorted out the problem about my previous post.
However now I am getting an error on this line and I do not know how to fix this:

  item["Project"].Text = value;          

An object reference not set to an instance of an object.

Thanks for helping.
Felice

[Princy]

Hi Felice,

I'm not able to replicate the issue at my end. The code works fine at my side. Please provide your full code snippet to try to replicate the issue.

Thanks,
Princy