$sql = "select seg_dtl_id from segmentation where seg_id = '1'";
 $rs = $db->query($sql);
[download]

Since this doesn't depend on any data, there's no need to do it all over again in the loop. Do it once outside the loop. Also figure out a way to write a single SQL query that does everything you need (shouldn't be hard with a JOIN), so that you don't have to talk to the database so often.