Date Columns conversion

Rowid:
Working with Rowids: rowidtochar(rowid) and chartorowid('AAABUeAAQAAACsjAAg')

Date Columns
a. Converting dates to show date with time: to_char( 'DD-MON-YYYY HH24:MI:SS')
For example: select to_char(sysdate, 'DD-MON-YYYY HH24:MI:SS') from dual;
b. Comparing date columns -- Sometimes handy to skip the time portion when searching for dates. You can use the trunc command to strip the time off. This resets the time to midnight.
For example: select to_char(trunc(sysdate), 'DD-MON-YYYY HH24:MI:SS') from dual;