Sum is not supported for type "System.Object"

[Rajeev]

I am getting this error

Sum is not supported for type "System.Object"

For testing purposes i am using one table only.

The table Design is

ProductID autonumber
ID  int
ProductName Varchar(100)
Price Varchar(150)

Then i also added DataType=DataType=System.Decimal then i get an error

A value of type 'String' cannot be converted to type 'Decimal?'

This is my ASPX code

<asp:Content ID="Content2" ContentPlaceHolderID="contentplaceholder1" runat="server">
    <telerik:RadScriptManager runat="server" ID="RadScriptManager1" />
    <telerik:RadSkinManager ID="QsfSkinManager" runat="server" ShowChooser="true" />
    <telerik:RadFormDecorator ID="QsfFromDecorator" runat="server" DecoratedControls="All"
        EnableRoundedCorners="false" />
    <telerik:RadAjaxManager ID="RadAjaxManager1" runat="server">
        <AjaxSettings>
            <telerik:AjaxSetting AjaxControlID="RadGrid1">
                <UpdatedControls>
                    <telerik:AjaxUpdatedControl ControlID="RadGrid1"></telerik:AjaxUpdatedControl>
                </UpdatedControls>
            </telerik:AjaxSetting>
        </AjaxSettings>
    </telerik:RadAjaxManager>
    <telerik:RadGrid ID="RadGrid1"
        Width="100%" AllowSorting="True"
        ShowFooter="True" PageSize="15" AllowPaging="True" AllowMultiRowSelection="True" ShowChooser="true"
        runat="server" GridLines="None" AutoGenerateColumns="False" CellSpacing="0" DataSourceID="ObjectDataSource1">
        <MasterTableView Width="100%" Summary="RadGrid table" RetrieveAllDataFields="false"
            DataSourceID="ObjectDataSource1">
            <CommandItemSettings ExportToPdfText="Export to PDF"></CommandItemSettings>
            <RowIndicatorColumn Visible="True" FilterControlAltText="Filter RowIndicator column">
            </RowIndicatorColumn>
            <ExpandCollapseColumn Visible="True" FilterControlAltText="Filter ExpandColumn column">
            </ExpandCollapseColumn>
            <Columns>
                <telerik:GridBoundColumn DataField="Productid" HeaderText="Productid" DataType="System.Int32"
                    SortExpression="Productid">
                </telerik:GridBoundColumn>
                <telerik:GridBoundColumn DataField="id" HeaderText="id" DataType="System.Int32" FilterControlAltText="Filter id column"
                    SortExpression="id" UniqueName="id">
                </telerik:GridBoundColumn>
                <telerik:GridBoundColumn DataField="ProductName" HeaderText="ProductName" FilterControlAltText="Filter ProductName column"
                    SortExpression="ProductName" UniqueName="ProductName">
                </telerik:GridBoundColumn>
                <telerik:GridBoundColumn DataField="Price" HeaderText="Price" SortExpression="Price" Aggregate="Sum" FooterText="Total price: ">
                </telerik:GridBoundColumn>
            </Columns>
            <EditFormSettings>
                <EditColumn FilterControlAltText="Filter EditCommandColumn column">
                </EditColumn>
            </EditFormSettings>
        </MasterTableView>
        <PagerStyle Mode="NextPrevAndNumeric"></PagerStyle>
        <FilterMenu EnableImageSprites="False">
        </FilterMenu>
    </telerik:RadGrid>
    <asp:ObjectDataSource ID="ObjectDataSource1" runat="server" SelectMethod="GetListProduct"
        TypeName="Business.ProductManager"></asp:ObjectDataSource>
</asp:Content>

 

/////////////////////////////////////////////////////////////////////////
 public static ProductList GetListProduct()
        {
            ProductList tempList = null;


            string sql = "SELECT * from Product";
            //using (SqlConnection myConnection = new SqlConnection(AppConfig.ConnectionString))
            using (SqlConnection myConnection = new SqlConnection(System.Configuration.ConfigurationManager.ConnectionStrings["NLayer"].ConnectionString))
            {
                using (SqlCommand myCommand = new SqlCommand(sql, myConnection))
                {
                    myConnection.Open();

                    using (SqlDataReader myReader = myCommand.ExecuteReader())
                    {
                        if (myReader.HasRows)
                        {
                            tempList = new ProductList();
                            while (myReader.Read())
                            {
                                tempList.Add(FillDataRecordProduct(myReader));
                            }
                        }
                        myReader.Close();
                    }
                }
                return tempList;

            }
        }


 private static Product FillDataRecordProduct(IDataRecord myDataRecord)
        {
            Product myUserTracking = new Product();

            myUserTracking.Productid = myDataRecord.GetInt32(myDataRecord.GetOrdinal("Productid"));
            myUserTracking.id = myDataRecord.GetInt32(myDataRecord.GetOrdinal("id"));
            myUserTracking.ProductName = myDataRecord.GetString(myDataRecord.GetOrdinal("ProductName"));

            myUserTracking.Price = myDataRecord.GetString(myDataRecord.GetOrdinal("Price"));


            return myUserTracking;
        }

         

[Eyup]

Hello Rajeev,

Currently, you are using a string type field for the Price column. Please note that Sum aggregate is supported only for numeric fields. Change the field to a numeric type and let me know about the result.

Kind regards,
Eyup
the Telerik team