C#

using (OleDbConnection connection = new OleDbConnection(excelConnectionString)) 

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.IO;
using System.Data.OleDb;
using System.Data.SqlClient;
using System.Data.Common;


namespace CHD_CALL_REGISTER
{
    public partial class Form1 : Form
    {
        SqlConnection con = new SqlConnection();
       
        protected void Page_Load(object sender, EventArgs e)
        {
            string str = "Data Source=INLGM84MV1;Initial Catalog=CHD;Integrated Security=True";
            SqlConnection con = new SqlConnection(str);
            //con.ConnectionString = @"Data Source=INLGM84MV1;Initial Catalog=CHD;Integrated Security=True";
        }
        public Form1()
        {
            InitializeComponent();
        }
        
        private void buttonBrowse_Click(object sender, EventArgs e)
        {
            OpenFileDialog openFileDialog1 = new OpenFileDialog();

            openFileDialog1.InitialDirectory = "C:\\";
            openFileDialog1.Title = "Browse Excel Files";

            openFileDialog1.CheckFileExists = true;
            openFileDialog1.CheckPathExists = true;

            openFileDialog1.DefaultExt = "xls";
            openFileDialog1.Filter = "Excel file (*.xls)|*.xls";
            //openFileDialog1.FilterIndex = 2;
            openFileDialog1.RestoreDirectory = true;

            openFileDialog1.ReadOnlyChecked = true;
            openFileDialog1.ShowReadOnly = true;

            if (openFileDialog1.ShowDialog() == DialogResult.OK)
            {
                textBox1.Text = openFileDialog1.SafeFileName;
                buttonexport.Enabled = true;
            }
        }

        private void openFileDialog1_FileOk(object sender, CancelEventArgs e)
        {

        }

        private void button2_Click(object sender, EventArgs e)
        {
            Close();
        }

        private void textBox1_TextChanged(object sender, EventArgs e)
        {
            if (string.IsNullOrEmpty(textBox1.Text))
            {
                buttonexport.Enabled = false;
            }

        }

        private void buttonexport_Click(object sender, EventArgs e)
        {
            // Connection String to Excel Workbook,Replace DataSource value to point to your excel file location
            string excelConnectionString = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source" + textBox1.Text + ";Extended Properties\"Excel 8.0;HDR=YES\"";


            // Create Connection to Excel Workbook
            using (OleDbConnection connection = new OleDbConnection(excelConnectionString))
            
            {
                OleDbCommand command = new OleDbCommand("Select * FROM [Sheet1$]", connection);

                connection.Open();

                // Create DbDataReader to Data Worksheet
                using (DbDataReader dr = command.ExecuteReader())
                {
                    // SQL Server Connection String
                    //string sqlConnectionString = "Data Source=localhost;Initial Catalog=MyDB;Integrated Security=True";

                    // Bulk Copy to SQL Server
                    using (SqlBulkCopy bulkCopy = new SqlBulkCopy(con))
                    {
                        bulkCopy.DestinationTableName = "EMP_TABLE";
                        bulkCopy.ColumnMappings.Add("EMPCODE", "EMPCODE");
                        bulkCopy.ColumnMappings.Add("EMP_NAME", "EMP_NAME");
                        bulkCopy.ColumnMappings.Add("BUSINESS_CODE", "BUSINESS_CODE");
                        bulkCopy.ColumnMappings.Add("JOIN_DT", "JOIN_DT");
                        bulkCopy.ColumnMappings.Add("HQ_NAME", "HQ_NAME");
                        bulkCopy.ColumnMappings.Add("ZONE_ID", "ZONE_ID");
                        bulkCopy.ColumnMappings.Add("DESIG", "DESIG");
                        bulkCopy.ColumnMappings.Add("BAND", "BAND");
                        bulkCopy.ColumnMappings.Add("DEPT_NAME", "DEPT_NAME");
                        bulkCopy.ColumnMappings.Add("EMP_STATUS", "EMP_STATUS");
                        bulkCopy.ColumnMappings.Add("SUP1", "SUP1");
                        bulkCopy.ColumnMappings.Add("SUP1NAME", "SUP1NAME");
                        bulkCopy.ColumnMappings.Add("SUP1HQ", "SUP1HQ");
                        bulkCopy.ColumnMappings.Add("SUP2", "SUP2");
                        bulkCopy.ColumnMappings.Add("SUP2NAME", "SUP2NAME");
                        bulkCopy.ColumnMappings.Add("SUP2HQ", "SUP2HQ");
                        bulkCopy.ColumnMappings.Add("SUP3", "SUP3");
                        bulkCopy.ColumnMappings.Add("SUP3NAME", "SUP3NAME");
                        bulkCopy.ColumnMappings.Add("SUP3HQ", "SUP3HQ");
                        bulkCopy.WriteToServer(dr);
                        MessageBox.Show("Data Exported To Sql Server Successfully");
                    }
                }
            }

        }
    }
}

private void barButtonItemStartRec_ItemClick(object sender, ItemClickEventArgs e)
        {
            barButtonItemStartRec.Enabled = !(barButtonItemStopRec.Enabled = true);            

            var dlg = new MainForm();
            BackgroundWorker recWorker = new BackgroundWorker();
            recWorker.DoWork += dlg.StartRec;
            recWorker.RunWorkerAsync();          
        }
        
private void barButtonItemStopRec_ItemClick(object sender, ItemClickEventArgs e)
        {            
            barButtonItemStartRec.Enabled = !(barButtonItemStopRec.Enabled = false);
            var dlg = new MainForm();
            dlg.StopRec();            
        }