Getting Data table from the Excel Sheet Using C#

        string connectionString = "";

        bool flag = true;

        object value;

        try

        {

            string fileName = Path.GetFileName(fb_master.PostedFile.FileName);

            string fileExtension = Path.GetExtension(fb_master.PostedFile.FileName);

            string folder = ConfigurationManager.AppSettings["TargetFiles"];

            string fileLocation = ConfigurationManager.AppSettings["TargetFiles"]+System.DateTime.Today.ToString("dd-MMyyyy")+"_"+ fileName;

            DirectoryInfo dir = new DirectoryInfo(folder);

            if (!dir.Exists)

                dir.Create();

            fb_master.SaveAs(fileLocation);

            if (fb_master.HasFile)

            {

                //Check whether file extension is xls or xslx

                if (fileExtension == ".xls")

                {

                    connectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + fileLocation + ";Extended Properties=\"Excel 8.0;HDR=Yes;IMEX=2\"";

                }

                else if (fileExtension == ".xlsx")

                {

                    //connectionString = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + fileLocation + ";Extended Properties=\"Excel 12.0;HDR=Yes;IMEX=1\"";

                    connectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + fileLocation + ";Extended Properties=\"Excel 8.0;HDR=Yes;IMEX=1\"";

                }

                //Create OleDB Connection and OleDb Command

                OleDbConnection con = new OleDbConnection(connectionString);

                OleDbCommand cmd = new OleDbCommand();

                cmd.CommandType = System.Data.CommandType.Text;

                cmd.Connection = con;

                OleDbDataAdapter dAdapter = new OleDbDataAdapter(cmd);

                DataTable dtExcelRecords = new DataTable();

                con.Open();

                DataTable dtExcelSheetName = con.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, null);

                string getExcelSheetName = dtExcelSheetName.Rows[0]["Table_Name"].ToString();

                cmd.CommandText = "SELECT * FROM [" + getExcelSheetName + "] where Finyear is not null ";

                dAdapter.SelectCommand = cmd;

                dAdapter.Fill(dtExcelRecords);

                con.Close();

          }

        }

        catch (Exception ex)

        {

            UserMessage.ShowUserMessage("Excel file cannot be uploaded.please check the data in Excel file.It may contains Null values.");

            _gb.ErrorLog(ex.Message);

        }