>我有一个包含三个ID和日期的表 我想从当前日期开始生成一年的日期，以及六个月之前和之后的日期 然后我想在这一年生成的卡兰达上绘制三个日期 我试过了
SELECT (TO_DATE(SYSDATE)-180) + ROWNUM DT
FROM (SELECT 1
FROM DUAL
CONNECT BY LEVEL <=180)
"月"的概念是可变的，因此您可能需要仔细检查"6个月"是否真的是您正在寻找的。如果您不知道日期数学的奇怪之处，它可能会给出意想不到的结果。
话虽如此，可以使用以下内容生成当前日期两侧包含 6 个月的日历。请注意，184 天是 6 个月跨度最长的时间段(7 月至 12 月(。
SELECT dt
FROM (SELECT TRUNC(SYSDATE - 184) + LEVEL AS dt
FROM dual
CONNECT BY LEVEL <= 369)
WHERE dt BETWEEN add_months(TRUNC(SYSDATE), -6) AND add_months(TRUNC(SYSDATE), 6);
按照你所说的字面意思：有一个包含 3 个 ID 及其日期的表格，你想绘制日历。
使用分层查询，日期生成为
SQL> with
2 threeid (id, datum) as
3 (select 1, date '2020-05-29' from dual union all
4 select 2, date '2020-01-01' from dual union all
5 select 3, date '2020-02-29' from dual
6 ),
7 cal as
8 (select add_months(datum, -6) + column_value - 1 datum
9 from threeid cross join
10 table(cast(multiset(select level from dual
11 connect by level <= add_months(datum, 6) - add_months(datum, -6)
12 ) as sys.odcinumberlist))
13 where id = 1 --> for the 1st ID; change that for other calendars
14 )
15 select * from cal order by datum;
DATUM
----------
29.11.2019
30.11.2019
01.12.2019
02.12.2019
03.12.2019
<snip>
25.11.2020
26.11.2020
27.11.2020
28.11.2020
366 rows selected.
如果你想绘制它，而不是#15行，你会使用它......
<snip>
15 select lpad(month, 20, ' ') month,
16 "Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"
17 from (select to_char(dt, 'fmMonthfm YYYY') month,
18 week,
19 max(decode(to_char(dt, 'd'), '1', lpad(to_char(dt, 'fmdd'), 2))) "Mon",
20 max(decode(to_char(dt, 'd'), '2', lpad(to_char(dt, 'fmdd'), 2))) "Tue",
21 max(decode(to_char(dt, 'd'), '3', lpad(to_char(dt, 'fmdd'), 2))) "Wed",
22 max(decode(to_char(dt, 'd'), '4', lpad(to_char(dt, 'fmdd'), 2))) "Thu",
23 max(decode(to_char(dt, 'd'), '5', lpad(to_char(dt, 'fmdd'), 2))) "Fri",
24 max(decode(to_char(dt, 'd'), '6', lpad(to_char(dt, 'fmdd'), 2))) "Sat",
25 max(decode(to_char(dt, 'd'), '7', lpad(to_char(dt, 'fmdd'), 2))) "Sun"
26 from ( select dt,
27 case when dt >= to_date(to_char(dt, 'dd/') ||'12/'||
28 to_char(sysdate,'yyyy'), 'dd/mm/yyyy')
29 and wk = '01'
30 then '53'
31 else wk
32 end week
33 from (select datum dt, to_char(datum, 'iw') wk
34 from cal
35 )
36 )
37 group by to_char(dt, 'fmMonthfm YYYY'), week
38 )
39 order by to_date( month, 'Month YYYY' ), to_number(week);
。并得到：
MONTH Mon Tue Wed Thu Fri Sat Sun
-------------------- -------- -------- -------- -------- -------- -------- --------
November 2019 29 30
December 2019 30 31
December 2019 1
December 2019 2 3 4 5 6 7 8
December 2019 9 10 11 12 13 14 15
December 2019 16 17 18 19 20 21 22
December 2019 23 24 25 26 27 28 29
January 2020 1 2 3 4 5
January 2020 6 7 8 9 10 11 12
January 2020 13 14 15 16 17 18 19
January 2020 20 21 22 23 24 25 26
January 2020 27 28 29 30 31
February 2020 1 2
February 2020 3 4 5 6 7 8 9
February 2020 10 11 12 13 14 15 16
February 2020 17 18 19 20 21 22 23
February 2020 24 25 26 27 28 29
March 2020 1
March 2020 2 3 4 5 6 7 8
March 2020 9 10 11 12 13 14 15
March 2020 16 17 18 19 20 21 22
March 2020 23 24 25 26 27 28 29
March 2020 30 31
April 2020 1 2 3 4 5
April 2020 6 7 8 9 10 11 12
April 2020 13 14 15 16 17 18 19
April 2020 20 21 22 23 24 25 26
April 2020 27 28 29 30
May 2020 1 2 3
May 2020 4 5 6 7 8 9 10
May 2020 11 12 13 14 15 16 17
May 2020 18 19 20 21 22 23 24
May 2020 25 26 27 28 29 30 31
June 2020 1 2 3 4 5 6 7
June 2020 8 9 10 11 12 13 14
June 2020 15 16 17 18 19 20 21
June 2020 22 23 24 25 26 27 28
June 2020 29 30
July 2020 1 2 3 4 5
July 2020 6 7 8 9 10 11 12
July 2020 13 14 15 16 17 18 19
July 2020 20 21 22 23 24 25 26
July 2020 27 28 29 30 31
August 2020 1 2
August 2020 3 4 5 6 7 8 9
August 2020 10 11 12 13 14 15 16
August 2020 17 18 19 20 21 22 23
August 2020 24 25 26 27 28 29 30
August 2020 31
September 2020 1 2 3 4 5 6
September 2020 7 8 9 10 11 12 13
September 2020 14 15 16 17 18 19 20
September 2020 21 22 23 24 25 26 27
September 2020 28 29 30
October 2020 1 2 3 4
October 2020 5 6 7 8 9 10 11
October 2020 12 13 14 15 16 17 18
October 2020 19 20 21 22 23 24 25
October 2020 26 27 28 29 30 31
November 2020 1
November 2020 2 3 4 5 6 7 8
November 2020 9 10 11 12 13 14 15
November 2020 16 17 18 19 20 21 22
November 2020 23 24 25 26 27 28
64 rows selected.
SQL>
(那个不错的日历查询最初(至少，我认为是这样(发布在 OraFAQ 网站上;我调整了它，希望它正确显示日期(