Getting quarters with two input date-parameters

Question

I have to find a way to get all the quarters between a startdate and an enddate, like 01-04-2009 (startdate) and 31-11-2009 (enddate). An extra condition is to count an extra quarter above the enddate, so the last quarter is 2010-01 (first quarter of 2010).
The desired result will be:
2009-02
2009-03
2009-04
2010-01
The start- and enddate are inputparameters.
How do I get this result?

Answer 1

Hi,
You're getting a quarter for each 3 values of LEVEL.
To get one more quarter, add 3 to the limit on LEVEL:
select distinct
        to_char(qdate,'YYYYQ') quarter
from      ( select  add_months ( to_date (:start_date, 'DD/MM/YYYY')
                        , m
                    ) qdate
       from        ( select level m
                from   dual
              connect by level < 3 +     -- Added
                                      ceil ( months_between ( to_date (:end_date,  'DD/MM/YYYY')
                                                             , to_date (:start_date,'DD/MM/YYYY')
order by quarter
;Edited by: Frank Kulash on Jan 22, 2010 9:09 AM
By the way, you don't need all those sub-queries.
SELECT     TO_CHAR ( ADD_MONTHS ( TO_DATE (:start_date, :date_format)
                      , 3 * (LEVEL - 1)
          , 'YYYYQ'
FROM     dual
CONNECT BY     LEVEL <= 1 + CEIL ( MONTHS_BETWEEN ( TO_DATE (:end_date,   :date_format)
                                                  , TO_DATE (:start_date, :date_format)
                            / 3
;