日历表

-- 当月的日历表

SQL> with x as
2   (select trunc(sysdate, 'mm') + level - 1 tdate,
3           to_char(trunc(sysdate, 'mm') + level - 1, 'iw') week,
4           to_char(trunc(sysdate, 'mm') + level - 1, 'dd') days,
5           to_char(trunc(sysdate, 'mm') + level - 1, 'd') weekday
6      from dual
7    connect by level <= 31)
8  select max(case when weekday = 2 then days end) Mon,
9         max(case when weekday = 3 then days end) Tus,
10         max(case when weekday = 4 then days end) Wed,
11         max(case when weekday = 5 then days end) Ths,
12         max(case when weekday = 6 then days end) Fri,
13         max(case when weekday = 7 then days end) Sat,
14         max(case when weekday = 1 then days end) Sun
15    from x
16   group by week
17   order by week
18  /
MO TU WE TH FR SA SU
-- -- -- -- -- -- --
01 02 03 04 05
06 07 08 09 10 11 12
13 14 15 16 17 18 19
20 21 22 23 24 25 26
27 28 29 30 31

 

--  当年的日历表

WITH x0 AS
(SELECT 2014 AS years FROM dual),
x1 AS
(SELECT to_date(years, 'yyyy') AS first_year,
add_months(to_date(years, 'yyyy'), 12) AS next_year
FROM x0),
x2 AS
/*枚举tdate*/
(SELECT first_year + LEVEL - 1 AS tdate
FROM x1
CONNECT BY LEVEL <= next_year - first_year),
x3 AS
(
/*取月份，及周信息*/
SELECT tdate,
to_char(tdate, 'mm') mon,
to_char(tdate, 'iw') week,
to_number(to_char(tdate, 'd')) we
FROM x2),
x4 AS
/*修正周*/
(SELECT tdate,
mon,
CASE
WHEN mon = '12' AND week = '01' THEN
'53'
ELSE
week
END AS week,
we
FROM x3)
SELECT CASE
WHEN lag(mon) over(ORDER BY week) = mon THEN
NULL
ELSE
mon
END AS mon,
week,
MAX(CASE we WHEN 2 THEN tdate END) mon,
MAX(CASE we WHEN 3 THEN tdate END) tue,
MAX(CASE we WHEN 4 THEN tdate END) wed,
MAX(CASE we WHEN 5 THEN tdate END) thr,
MAX(CASE we WHEN 6 THEN tdate END) fri,
MAX(CASE we WHEN 7 THEN tdate END) sat,
MAX(CASE we WHEN 1 THEN tdate END) sun
FROM x4
GROUP BY mon, week
ORDER BY 2

 

 -- 求季度

 

SQL> select level quarter,
2         add_months(trunc(sysdate, 'y'), level * 3 - 3) start_mon,
3         add_months(trunc(sysdate, 'y'), level * 3) - 1 end_mon
4    from dual
5  connect by level <= 4
6  /
QUARTER START_MON  END_MON
---------- ---------- ----------
1 2014-01-01 2014-03-31
2 2014-04-01 2014-06-30
3 2014-07-01 2014-09-30
4 2014-10-01 2014-12-31