Display min, max and average records in textbox in c#

Here I will show you how to Display min, max and average records in textbox in c#.

Here I will show you how to Display min, max and average records in textbox in c#.
 
 Program
 
 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 Display_min_max_avg_records_in_textbox
 {
     public partial class Form1 : Form
     {
         string ConnectionString = System.Configuration.ConfigurationSettings.AppSettings["dsn"];
         OleDbCommand com;
         OleDbDataAdapter oledbda;
         DataSet ds = new DataSet();
         string str;             
         public Form1()
         {
             InitializeComponent();
         }
  
         private void Form1_Load(object sender, EventArgs e)
         {
             OleDbConnection con = new OleDbConnection(ConnectionString);
             con.Open();
             str = "select * from student";
             com = new OleDbCommand(str, con);
             oledbda = new OleDbDataAdapter(com);
             ds = new DataSet();
             oledbda.Fill(ds, "student");
             dataGridView1.DataSource = ds;
             dataGridView1.DataMember = "student";
             con.Close(); 
         }
  
         private void button1_Click(object sender, EventArgs e)
         {
             OleDbConnection con = new OleDbConnection(ConnectionString);
             con.Open();
             str = "select max(smarks)from student";
             com = new OleDbCommand(str, con);
             textBox1.Text = com.ExecuteScalar().ToString();
             con.Close(); 
         }
  
         private void button2_Click(object sender, EventArgs e)
         {
             OleDbConnection con = new OleDbConnection(ConnectionString);
             con.Open();
             str = "select min(smarks)from student";
             com = new OleDbCommand(str, con);
             textBox2.Text = com.ExecuteScalar().ToString();
             con.Close(); 
         }
  
         private void button3_Click(object sender, EventArgs e)
         {
             OleDbConnection con = new OleDbConnection(ConnectionString);
             con.Open();
             str = "select avg(smarks)from student";
             com = new OleDbCommand(str, con);
             textBox3.Text = com.ExecuteScalar().ToString();
             con.Close(); 
         }
     }
 }
 
 Output

 
 
 Thanks