Filtering records from 1st combobox to 2nd combobox and 2nd to 3rd combobox

Is this for an online (ASP.Net) application or desktop?

Note that this is often called cascading, as in cascading comboboxes. Do you use TableAdapters? I posted a sample that uses TableAdapters in a thread a few months ago. Otherwise there are articles in this web site that decribe other ways to do it.

Hi Arvind,


Try this...


<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Default.aspx.cs" Inherits="Country_state_city._Default" %>





   


   

   

   
   
  
       
          
                              ForeColor="Red" Width="100px">
                                 AppendDataBoundItems="true"  runat="server" Height="20px" Width="156px"
                   onselectedindexchanged="ddlcountry_SelectedIndexChanged" Font-Bold="True"
                   ForeColor="#FF9900">
           
       

     
      
     
  
       


       
    
                  ForeColor="Red" Width="100px">
                    AppendDataBoundItems ="true"  runat="server" Height="20px"
Width="155px" onselectedindexchanged="ddlstate_SelectedIndexChanged" Font-Bold="True"
             ForeColor="#993300">
      
    
    
       
       
    
       

      
        
                ForeColor="Red" Width="100px">  
                  runat="server" Height="20px" Width="155px" Font-Bold="True" ForeColor="#CCCC00">
     
  
  
    
 
   

   

using System;
using System.Collections;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;
using System.Data.SqlClient;
namespace Country_state_city
{
    public partial class _Default : System.Web.UI.Page
    {
        string strConnString = ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString;
        string str;
        SqlCommand com;
        SqlDataAdapter sqlda;
        DataSet ds;

        protected void Page_Load(object sender, EventArgs e)
        {
            if (!IsPostBack)
            {
                bindcountry();
            }
        }

        protected void ddlcountry_SelectedIndexChanged(object sender, EventArgs e)
        {
            bindstate();
        }

        protected void ddlstate_SelectedIndexChanged(object sender, EventArgs e)
        {
            bindcity();
        }


        public void bindcountry()
        {
            SqlConnection con = new SqlConnection(strConnString);
            con.Open();
            str = "select CountryId,CountryName from Country";
            com = new SqlCommand(str, con);
            sqlda = new SqlDataAdapter(com);
            ds = new DataSet();
            sqlda.Fill(ds, "Country");
            ddlcountry.Items.Clear();
            ddlcountry.Items.Add("--Select--");
            ddlcountry.DataValueField = "CountryId";
            ddlcountry.DataTextField = "CountryName";
            ddlcountry.DataSource = ds;
            ddlcountry.DataMember = "Country";
            ddlcountry.DataBind();
            con.Close();
        }
        public void bindstate()
        {
            SqlConnection con = new SqlConnection(strConnString);
            con.Open();
            str = "select StateId,StateName from State where Country_Id='" + ddlcountry.SelectedValue + "'";
            com = new SqlCommand(str, con);
            sqlda = new SqlDataAdapter(com);
            ds = new DataSet();
            sqlda.Fill(ds, "State");
            ddlstate.Items.Clear();
            ddlstate.Items.Add("--Select--");
            ddlstate.DataValueField = "StateId";
            ddlstate.DataTextField = "StateName";
            ddlstate.DataSource = ds;
            ddlstate.DataMember = "State";
            ddlstate.DataBind();
            con.Close();
        }
        public void bindcity()
        {
            SqlConnection con = new SqlConnection(strConnString);
            con.Open();
            str = "select CityId,CityName from City where State_Id ='" + ddlstate.SelectedValue + "'";
            com = new SqlCommand(str, con);
            sqlda = new SqlDataAdapter(com);
            ds = new DataSet();
            sqlda.Fill(ds, "City");
            ddlcity.Items.Clear();
            ddlcity.Items.Add("--Select--");
            ddlcity.DataValueField = "CityId";
            ddlcity.DataTextField = "CityName";
            ddlcity.DataSource = ds;
            ddlcity.DataMember = "City";
            ddlcity.DataBind();
            con.Close();
        }


    }
}




Thanks
If this post helps you mark it as answer

sample code

As per Kunal Vaishya  response

In first drop down do this

select StateName from tablename where countryID='"+ddl1.selectedvalue+"'

you will get the required state names fill the to a dataset and bind to ddl2, like that for ddl3 too

This will work if you are maintaining a relation between each table 

Dear

First Set
i Amuse that  
Combo1 Country
Combo2 State
Combo3 City


TableCity
CID
CNAme
SID

TableState
SID
SName
CNId

TableCountry
CNID
CNNAme

First When you select the combo value of COuntry the on Selected value Change you can filter State and combo value of State the on Selected value Change you can filter City

you can also youse selected index changed event to do like this

Use

ComboBox1.DataSource = DataSet.Tables["City"].DefaultView;
ComboBox1.DisplayMember = "CName";
ComboBox1.ValueMember = "CId";
 

3 differnet table in the database for the 3 different form.