Oracle: Facebook Style Time of Post - 2

Try This for Demo

SELECT
    distinct
    MYDATE,
    CASE
        WHEN FLOOR(((SYSDATE) - MYDATE) * 24 * 60) < 1
            THEN 'Arrived ' || FLOOR(((SYSDATE ) - MYDATE) * 24 * 60 * 60) ||  ' seconds ago'
        WHEN FLOOR(((SYSDATE) - MYDATE) * 24 * 60) < 60
            THEN 'Arrived ' || FLOOR(((SYSDATE ) - MYDATE) * 24 * 60) ||  ' minute ago'
        WHEN FLOOR(((SYSDATE) - MYDATE) * 24) < 4
            THEN 'Arrived ' || FLOOR(((SYSDATE ) - MYDATE) * 24) || ' hour ago'
        ELSE
            'Arrived on ' || to_char(MYDATE,'DD-Mon-YYYY HH24:MI:SS')
    END AS MYMSG
FROM
    (select (sysdate - 1/level) MYDATE from dual connect by level <= 24*60*60)
ORDER BY MYDATE DESC


Oracle: Dates Difference in days, hours, minutes & seconds
http://nimishgarg.blogspot.com/2009/12/get-dates-difference-in-days-hours.html

Oracle SQL: Date Difference in Days, Months and Years
http://nimishgarg.blogspot.com/2010/08/oracle-sql-date-difference-in-days.html

Oracle: Facebook Style Time of Post
http://nimishgarg.blogspot.com/2010/02/oracle-sql-facebook-style-time-of-post.html

Oracle: Facebook Style Time of Post - 2
http://nimishgarg.blogspot.com/2010/02/oracle-sql-facebook-style-time-of-post_23.html

Oracle: Some Important Date Queries
http://nimishgarg.blogspot.com/2010/11/oracle-some-important-date-queries.html