in three tier how to populate ddl based on another ddl selec

Question

in three tier architecture how to populate ddl based on another ddl selected value

Satyapriya Nayak · Answer

using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Linq; using System.Text; using System.Windows.Forms; using System.Data.OleDb; namespace Combobox { public partial class Form1 : Form { string ConnectionString = System.Configuration.ConfigurationSettings.AppSettings["dsn"]; OleDbCommand com; OleDbDataAdapter oda; DataSet ds; string str; public Form1() { InitializeComponent(); } private void Form1_Load(object sender, EventArgs e) { comboBox1.Items.Add("Choose CourseID"); OleDbConnection con = new OleDbConnection(ConnectionString); con.Open(); str = "select * from Courses"; com = new OleDbCommand(str, con); OleDbDataReader reader = com.ExecuteReader(); while (reader.Read()) { comboBox1.Items.Add(reader["CourseID"]); } } private void comboBox1_SelectedIndexChanged(object sender, EventArgs e) { comboBox2.Items.Clear(); OleDbConnection con = new OleDbConnection(ConnectionString); con.Open(); str = "select * from Students where CourseID='" + comboBox1.Text.Trim() + "'"; com = new OleDbCommand(str, con); OleDbDataReader reader = com.ExecuteReader(); while (reader.Read()) { comboBox2.Items.Add(reader["FirstName"].ToString()); } con.Close(); reader.Close(); } } }

venkata kumar · Answer

hi first ddl selected change event pass values and get values and bind to second ddl

in three tier how to populate ddl based on another ddl selec

Answers (2)