使用oracle sql生成一年日期

qvk1mo1f  于 2021-08-13  发布在  Java
关注(0)|答案(2)|浏览(331)

我有一个表,有三个id和日期,我想从当前日期生成一年的日期,在六个月之前和之后,然后我想在这一年生成的日历上绘制三个日期

SELECT (TO_DATE(SYSDATE)-180) + ROWNUM DT
  FROM (SELECT 1
          FROM DUAL
       CONNECT BY LEVEL <=180)
vd8tlhqk

vd8tlhqk1#

“月”的概念是可变的,所以你可能需要再次检查“6个月”是否真的是你想要的。如果你不知道日期数学的奇怪之处,它会产生意想不到的结果。
也就是说,在当前日期的两边都包含6个月的日历可以用以下公式生成。请注意,184天是6个月(7月至12月)所能持续的最长时间。

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);
drkbr07n

drkbr07n2#

照你说的做:有一个表有3个ID和它们的日期,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.

如果你想画出来,用这个代替15号线。。。

<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);

... 然后得到:

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>

(这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,希望它能正确显示日期)

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