Excel µ¼Èësqlserver c#

using System.Data.SqlClient;
using System.Data.OleDb;
 private void button1_Click(object sender, EventArgs e)
        {
OleDbConnection conn = null;
            try
            {
                string path = "./Users.xls";
                string strConn;
                strConn = "Provider=Microsoft.Jet.OLEDB.4.0;" +
                    "Data Source=" + path + ";" +
                "Extended Properties='Excel 8.0;HDR=Yes;IMEX=1;'";
                conn = new OleDbConnection(strConn);
                conn.Open();
                string Sql = "select * from [Users$]";
                System.Data.OleDb.OleDbCommand cmd = new System.Data.OleDb.OleDbCommand();
                OleDbDataAdapter ddp = new OleDbDataAdapter(Sql, conn);
                DataTable dt = new DataTable();
                ddp.Fill(dt);
                ddp.D