string sql="";
dbhelper.ExecuteNonQuery(sql);
DataTable dt = dbhelper.GetDataTable(sql);
if (dt != null && dt.Rows.Count > 0)
{
SqlBulkCopy bcp = new SqlBulkCopy("server=.;database=Service;uid=sa;pwd=123456");
bcp.DestinationTableName = "InventoryDiff";
bcp.WriteToServer(dt);
}