I have a simple webform in which i have placed a DevExpress Gridview {}, i did not used code to bind this gridview i just used the designer to bind this gridview to a table , I have two tables in my database, one of my column is having a nature like its value can be any one from Three {i mean its value can be from dropdownlist or comboBox } so i put  Edit Item Template and place combo box in it and bind this combo box from anther table {Second table}
ID="ComboBoxProvider" runat="server" Width="325px" TextField="StaffName" ValueField="StaffID" ValueType="System.String" IncrementalFilteringMode="StartsWith" EnableIncrementalFiltering="True" DataSourceID="SqlDataSource2">
 Now On insertion all other columns are inserted fine except this column and on update the same case all other are updating except this column , I have no code behind code just using the designer below is the over all code of aspx page.
<%@ Page Language="C#" AutoEventWireup="true" CodeFile="Default.aspx.cs" Inherits="_Default" %>
<%@ Register Assembly="DevExpress.Web.v13.2, Version=13.2.5.0, Culture=neutral, PublicKeyToken=b88d1754d700e49a" Namespace="DevExpress.Web.ASPxGridView" TagPrefix="dx" %>
<%@ Register assembly="DevExpress.Web.v13.2, Version=13.2.5.0, Culture=neutral, PublicKeyToken=b88d1754d700e49a" namespace="DevExpress.Web.ASPxEditors" tagprefix="dx" %>
ID="ComboBoxProvider" runat="server" Width="325px" TextField="StaffName" ValueField="StaffID" ValueType="System.String" IncrementalFilteringMode="StartsWith" EnableIncrementalFiltering="True" DataSourceID="SqlDataSource2">