Finding the Seventh Weekday.

Question

Hi,
I have this requirement where I am required to run a program if today is the seventh weekday of the month. To get to that, I kind of wrote this sql. I know this is long-winded, but, just checking if there is another way for me to write this:
SELECT actual_date seventh_weekday
  FROM (SELECT CASE
                 WHEN to_char(actual_date,
                              'dy') IN ('mon',
                                        'tue',
                                        'wed',
                                        'thu',
                                        'fri') THEN
                  1
                 ELSE
                  0
               END is_it_weekday,
               actual_date,
               SUM(CASE
                     WHEN to_char(actual_date,
                                  'dy') IN ('mon',
                                            'tue',
                                            'wed',
                                            'thu',
                                            'fri') THEN
                      1
                     ELSE
                      0
                   END) over(ORDER BY actual_date rows BETWEEN unbounded preceding AND CURRENT ROW) is_this_seventh_weekday
          FROM (SELECT trunc(SYSDATE,
                             'month') + LEVEL - 1 actual_date
                  FROM dual
                CONNECT BY trunc(SYSDATE,
                                 'month') + LEVEL - 1 <= last_day(SYSDATE)))
WHERE is_this_seventh_weekday = 7
   AND to_char(actual_date,
               'dy') IN ('mon', 'tue', 'wed', 'thu', 'fri')

Answer 1

As an illustration. It's pretty common superstition around here that fridays are not lucky days, especially to get something started and it's even worse when they occur on the 13th of the month. Suppose you have to find those worst cases for the current year. you can:
with     
current_year as  -- generate all days of the year (365 or 366 rows)
(select trunc(sysdate,'year') + level - 1 as the_date     
   from dual     
connect by level <= add_months(trunc(sysdate,'year'),12) - trunc(sysdate,'year')
select the_date
  from current_year
where to_char(the_date,'dy') = 'fri'
   and to_char(the_date,'dd') = '13'
with     
current_year as  -- generate all fridays of the year (52 or 53 rows)
(select trunc(sysdate,'year') + 7 * (level - 1) + to_number(to_char(next_day(trunc(sysdate,'year'),'friday'),'dd')) - 1 as the_date     
   from dual
connect by level <= floor((add_months(next_day(trunc(sysdate,'year'),'friday'),12) - next_day(trunc(sysdate,'year'),'friday')) / 7)
select the_date
  from current_year
where to_char(the_date,'dd') = '13'
with     
current_year as  -- generate all 13th of the months of the year (12 rows)
(select to_date('13.' || to_char(level) || '.' || to_char(sysdate,'yyyy'),'dd.mm.yyyy') as the_date     
   from dual     
connect by level <= 12
select the_date
  from current_year
where to_char(the_date,'dy') = 'fri'Regards
Etbin