How to show related Data in Textbox using C#

Here I will show you how to Show Related Data In Textbox When We Click Related Item In Combobox In Csharp.

Create a table named employee having fileds empid Text, empname Text, sal Number , empaddress Text , phoneno Number in Ms-access.

Method 1:

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_textbox_data
{
    public partial class Form1 : Form
    {
        string ConnectionString = System.Configuration.ConfigurationSettings.AppSettings["dsn"];
        OleDbCommand com;
        OleDbDataAdapter oledbda;
        DataSet ds;
        string str;
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {

           OleDbConnection con = new OleDbConnection(ConnectionString);
            str = "select * from employee";
            com = new OleDbCommand(str, con);
            oledbda = new OleDbDataAdapter(com);
            ds = new DataSet();
            oledbda.Fill(ds, "employee");
            comboBox1.DataSource = ds.Tables["employee"];
            comboBox1.DisplayMember = "empid";
            comboBox1.Text = "select";
            textBox1.Text = "";
            textBox2.Text = "";
            textBox3.Text = "";
            textBox4.Text = "";

        }

        private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
        {
           OleDbConnection con = new OleDbConnection(ConnectionString);
            con.Open();
            str = "select * from employee where empid='" +  comboBox1.Text.Trim() + "'";
            com = new OleDbCommand(str, con);
            OleDbDataReader reader = com.ExecuteReader();

            if (reader.Read())
            {
                textBox1.Text = reader["empname"].ToString();
                textBox2.Text = reader["sal"].ToString();
                textBox3.Text = reader["empaddress"].ToString();
                textBox4.Text = reader["phoneno"].ToString();
            }
 
            con.Close();
            reader.Close();
      
           
 
        }
    }
}

Method 2:

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_textbox_data
{
    public partial class Form2 : Form
    {
        string ConnectionString = System.Configuration.ConfigurationSettings.AppSettings["dsn"];
        OleDbCommand com;
        OleDbDataAdapter oledbda;
        DataSet ds;
        string str;
        public Form2()
        {
            InitializeComponent();
        }

        private void Form2_Load(object sender, EventArgs e)
        {
           OleDbConnection con = new OleDbConnection(ConnectionString);
            con.Open();
            str = "select * from employee";
            com = new OleDbCommand(str, con);
            OleDbDataReader reader = com.ExecuteReader();
            while (reader.Read())
            {
                comboBox1.Items.Add(reader["empid"]);
            }
            reader.Close();
            con.Close();
            comboBox1.Text = "select";
            textBox1.Text = "";
            textBox2.Text = "";
            textBox3.Text = "";
            textBox4.Text = "";
        }

        private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
        {
           OleDbConnection con = new OleDbConnection(ConnectionString);
            con.Open();
            str = "select * from employee where empid='" + comboBox1.Text.Trim() + "'";
            com = new OleDbCommand(str, con);
            OleDbDataReader reader = com.ExecuteReader();

            if (reader.Read())
            {
                textBox1.Text = reader["empname"].ToString();
                textBox2.Text = reader["sal"].ToString();
                textBox3.Text = reader["empaddress"].ToString();
                textBox4.Text = reader["phoneno"].ToString();
            }

            con.Close();
            reader.Close();

        }
    }
}

Method 3:

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_textbox_data
{
    public partial class Form3 : Form
    {
        string ConnectionString = System.Configuration.ConfigurationSettings.AppSettings["dsn"];
        OleDbCommand com;
        OleDbDataAdapter oledbda;
        DataSet ds;
        string str;
        DataTable dt;
        public Form3()
        {
            InitializeComponent();
        } 

        private void Form3_Load(object sender, EventArgs e)
        {
           OleDbConnection con = new OleDbConnection(ConnectionString);
            con.Open();
            str = "select * from employee";
            com = new OleDbCommand(str, con);
            oledbda = new OleDbDataAdapter(com);
            ds = new DataSet();
            oledbda.Fill(ds, "employee");
            dt = ds.Tables["employee"];
            int i;
            for (i = 0; i <= dt.Rows.Count - 1; i++)
            {
                comboBox1.Items.Add(dt.Rows[i].ItemArray[0]);
            }
            con.Close();
            comboBox1.Text = "select";
            textBox1.Text = "";
            textBox2.Text = "";
            textBox3.Text = "";
            textBox4.Text = "";
        }
        private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
        {
           OleDbConnection con = new OleDbConnection(ConnectionString);
            con.Open();
            str = "select * from employee where empid='" + comboBox1.Text.Trim() + "'";
            com = new OleDbCommand(str, con);
            OleDbDataReader reader = com.ExecuteReader();

            if (reader.Read())
            {
                textBox1.Text = reader["empname"].ToString();
                textBox2.Text = reader["sal"].ToString();
                textBox3.Text = reader["empaddress"].ToString();
                textBox4.Text = reader["phoneno"].ToString();
            }

            con.Close();
            reader.Close();
        }
    }
}

Running the program

After running the program when you select any empid from the combobox its corresponding values will be shown.



Thanks for reading.