Querying school databases

This is the application I created for my personal use. I need some quality testing of this application. If you see some errors or any lengthy coding (it's already lengthy), and it needs to be shortened please tell me. I would love to learn new things; as I'm a newbie, I have made lots of mistakes here.

`using System;
using System.Windows.Forms;
using System.Data.SqlClient;
using System.Data;
using System.Data.Common;
using System.Collections.Generic;
using System.Configuration;

namespace Table_creator
{

public partial class CreateTable : Form
{
private BindingSource bindingSource1 = new BindingSource();
public CreateTable()
{
InitializeComponent();
}

private void button1_Click(object sender, EventArgs e)
{
SqlConnection con = new SqlConnection(@"Data Source=.\SQLEXPRESS;AttachDbFilename=" + Application.StartupPath + "\\database.mdf;Integrated Security=True;Connect Timeout=30;User Instance=True");
string qry = "CREATE TABLE [" + txtCreateTable.Text + "] (StudentName NVARCHAR(50),ContactNo nchar(11),FathersNo nchar(11), MothersNo nchar(11), Email nvarchar(100))";
SqlCommand cmd = new SqlCommand(qry, con);

try
{
con.Open();
cmd.ExecuteNonQuery();
MessageBox.Show("Success! Updated");
ListTables();
GetData();
}

catch (System.Exception ex)
{
MessageBox.Show("Failed");
txtCreateTable.Focus();
}

finally
{
con.Close();
}
}

private void ListTables()
{
try
{
SqlConnection con = new SqlConnection(@"Data Source=.\SQLEXPRESS;AttachDbFilename=" + Application.StartupPath + "\\database.mdf;Integrated Security=True;Connect Timeout=30;User Instance=True");

con.Op

First Principal of coding is DRY (do not repeat yourself ). so if you are repeating your code , encapsulate in one method or class. and call that method using differnt paramerter as per need.

Second, Opening and disposing a connection is equally important.

I have changed only one operation.

public class DataHelper
    {
        private const string ConnectionString = "PutYouConnectionString";

        public static DataTable ExecuteDataSet(string sql,params SqlParameter[] parameters)
        {
            using (var connection = new SqlConnection(ConnectionString))
            {
                using (var command = new SqlCommand(sql))
                {
                    command.Connection = connection;
                    if (parameters != null)
                    {
                        command.Parameters.AddRange(parameters);
                    }
                    var dbAdapter = new SqlDataAdapter(command);
                    var dataRecords = new DataTable();
                    dbAdapter.Fill(dataRecords);
                    return dataRecords;
                }
            }
        }

        public static void ExecuteNonQuery(string sql,params SqlParameter[] parameters)
        {
            using (var connection = new SqlConnection(ConnectionString))
            {
                using (var command = new SqlCommand(sql))
                {
                    command.Connection = connection;
                    if (parameters != null)
                    {
                        command.Parameters.AddRange(parameters);
                    }
                    command.ExecuteNonQuery();
                }
            }
        }

    }

    public class DataService
    {
        public void CreateTable(string tableName)
        {
            var sql = "CREATE TABLE [" + tableName +
                      "] (StudentName NVARCHAR(50),ContactNo nchar(11),FathersNo nchar(11), MothersNo nchar(11), Email nvarchar(100))";
            DataHelper.ExecuteNonQuery(sql);
        }
    }

StackExchange Code Review Q#59770, answer score: 7