ASP.NET using C#

Question

If i had a two dropdown list box... when i select a first dropdown list value ( If i click India) the next next dropdown listbox automatically bring the value present in MSSQL column "State".. how could i make it... please send example Using C#....

Satyapriya Nayak · Answer

Imports System.Data Imports System.Data.SqlClient Partial Class _Default Inherits System.Web.UI.Page Dim strConnString As String = System.Configuration.ConfigurationManager.ConnectionStrings.Item(ConnectionString).ToString() Dim con As New SqlConnection(strConnString) Dim str As String Dim com As SqlCommand Protected Sub Page_Load(ByVal sender As Object ByVal e As System.EventArgs) Handles Me.Load If Not IsPostBack Then con.Open() str = select * from area com = New SqlCommand(str con) Dim reader As SqlDataReader = com.ExecuteReader While reader.Read DropDownList1.Items.Add(reader(city)) End While reader.Close() con.Close() End If DropDownList2.Items.Clear() DropDownList3.Items.Clear() TextBox1.Text =  End Sub Protected Sub DropDownList1_SelectedIndexChanged(ByVal sender As Object ByVal e As System.EventArgs) Handles DropDownList1.SelectedIndexChanged con.Open() str = select * from area where city=' & DropDownList1.SelectedValue & ' com = New SqlCommand(str con) Dim reader As SqlDataReader = com.ExecuteReader Do While reader.Read DropDownList2.Items.Add(reader(state)) DropDownList3.Items.Add(reader(country)) TextBox1.Text = reader(stdcode) Loop reader.Close() con.Close() End Sub End Class

Manoj Tandon · Answer

First Enable AutoPatsBack of DropDownList after that in Selected_index changed event of this DDL Write Code as Below protected void DropDownList1_SelectedIndexChanged(object sender EventArgs e) { SqlDataAdapter da; DataSet ds = new DataSet(); try { da = new SqlDataAdapter(select book_Id book_name from book where category_name = ' + DropDownList1.SelectedItem.Text + ' your connection string); da.Fill(ds); DropDownList2.DataTextField = bokk_name; DropDownList2.DataValueField = book_Id; DropDownList2.DataSource = ds.Tables[0]; DropDownList2.DataBind(); } catch (Exception) { throw; } }

Sam Hobbs · Answer

Probably what you are trying to do is a master/detail type of form.

Zoran Horvat · Answer

You should populate the second drop down list with values from MSSQL database and then handle appropriate event on the first list (e.g. SelectedValueChanged) to set second list's value to the same value as first list has. More elaborate solution is to keep two- or three-letter ISO country codes behind both lists (so that value shown is country name and value selected is country code) and to operate with ISO codes rather than country names. Zoran