Insert Bulk Data in SQL Server Table from any Data Source using C#

Background

Few days back , I got a requirement from client says that ,they had plenty of useful excel files and they want to store that in Sql server and view it in a grid view. Each and every excel files had more than 1000 rows , and it I was very difficult to insert the data manually. So I decided to automate it through code and I wrote the below code.

C# Code

public static DataSet Bindgrid_StoreInSQL(string path)
{
    string strFileType = Path.GetExtension(path).ToLower();
    string connString = "";
    if (strFileType.Trim() == ".xls")
    {
        connString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + path + ";Extended Properties=\"Excel 8.0;HDR=Yes;IMEX=2\"";
    }
    else if (strFileType.Trim() == ".xlsx")
    {
        connString = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + path + ";Extended Properties=\"Excel 12.0;HDR=Yes;IMEX=2\"";
    }
    string query = "SELECT * FROM [Sheet1$]";
    OleDbConnection conn = new OleDbConnection(connString);
    OleDbCommand cmd = new OleDbCommand(query, conn);
    OleDbDataAdapter da = new OleDbDataAdapter(cmd);
    DataSet ds = new DataSet();
    da.Fill(ds);
    DataTable Exceldt = ds.Tables[0];
    //creating object of SqlBulkCopy
    SqlBulkCopy objbulk = new SqlBulkCopy(OneStopMethods_Common.constring_Property);
    //assigning Destination table name
    objbulk.DestinationTableName = "Tern_boq";
    objbulk.ColumnMappings.Add("ID", "ID");
    objbulk.ColumnMappings.Add("Bill_No", "Bill_No");
    objbulk.ColumnMappings.Add("Page_No", "Page_No");
    objbulk.ColumnMappings.Add("ItemNo", "ItemNo");
    objbulk.ColumnMappings.Add("Description", "Description");
    objbulk.ColumnMappings.Add("BOQ_Qty", "BOQ_Qty");
    objbulk.ColumnMappings.Add("UNIT", "UNIT");
    objbulk.ColumnMappings.Add("Category1", "Category1");
    objbulk.ColumnMappings.Add("Category2", "Category2");
    objbulk.ColumnMappings.Add("Category3", "Category3");
    objbulk.ColumnMappings.Add("Estimated_UnitRate", "Estimated_UnitRate");
    objbulk.ColumnMappings.Add("Estimated_Amount", "Estimated_Amount");
    //inserting Datatable Records to DataBase
    conn.Open();
    objbulk.WriteToServer(Exceldt);
    SqlDatabase obj = new SqlDatabase(OneStopMethods_Common.constring_Property);
    string selquery = " select * from Tern_boq";
    return obj.ExecuteDataSet(CommandType.Text, selquery);
}