SQL query to find difference between two time data

[aryasen]

Hi Binoy,
This will also achieves the same, but in a single query.

SELECT TO_CHAR(TRUNC((( to_date(to_char(sysdate,'DD-MON_YYYY')||' 10:30:00','DD-MON_YYYY HH24:MI:SS' ) -
to_date(to_char(sysdate,'DD-MON_YYYY')||' 09:45:00','DD-MON_YYYY HH24:MI:SS' ) ) * 24*60*60)/60/60),'09') ||':'||
TO_CHAR(TRUNC(MOD((( to_date(to_char(sysdate,'DD-MON_YYYY')||' 10:30:00','DD-MON_YYYY HH24:MI:SS' ) -
to_date(to_char(sysdate,'DD-MON_YYYY')||' 09:45:00','DD-MON_YYYY HH24:MI:SS' ) ) * 24*60*60),3600)/60),'09') ||':'||
TO_CHAR(MOD(MOD((( to_date(to_char(sysdate,'DD-MON_YYYY')||' 10:30:00','DD-MON_YYYY HH24:MI:SS' ) -
to_date(to_char(sysdate,'DD-MON_YYYY')||' 09:45:00','DD-MON_YYYY HH24:MI:SS' ) ) * 24*60*60),3600),60),'09') as "HH:MI:SS"
FROM dual;