sql - 在Oracle SQL中计算手动的年数

我有一个日期列，因此我需要在oracle中计算出他们当年的星期数的另一列，星期应该是从星期日的第一天到星期六。

例如本年度

Week 1 : 1 Jan 2020 (Wednesday) - 4 Jan 2020(Saturday)


Week 2 : 5 Jan 2020 (Sunday)        - 11 Jan 2020(Saturday)

. . . . .


Week 5 : 26 Jan 2020 (Sunday) - 1 Feb 2020 (Saturday)

等等...

最佳答案

您需要使用层次结构查询编写自己的逻辑。

类似于以下内容:

SQL> SELECT WEEKNUMBER,
  2  WEEK_START,
  3  CASE WHEN WEEKNUMBER = 1 THEN FIRST_WEEKEND ELSE WEEK_START + 6 END AS WEEK_END
  4  FROM
  5  (SELECT
  6      CASE
  7          WHEN LEVEL = 1 THEN FIRST_DAY
  8          ELSE FIRST_WEEKEND + ( LEVEL - 2 ) * 7 + 1
  9      END AS WEEK_START,
 10      FIRST_WEEKEND,
 11      LEVEL AS WEEKNUMBER
 12  FROM
 13      ( SELECT
 14              TRUNC(SYSDATE, 'YEAR') FIRST_DAY,
 15              NEXT_DAY(TRUNC(SYSDATE, 'YEAR'), 'SATURDAY') FIRST_WEEKEND
 16          FROM DUAL )
 17  CONNECT BY
 18      CASE WHEN LEVEL = 1 THEN FIRST_DAY
 19          ELSE FIRST_WEEKEND + ( LEVEL - 2 ) * 7 + 1
 20      END < ADD_MONTHS(TRUNC(SYSDATE, 'YEAR'), 12));

WEEKNUMBER WEEK_STAR WEEK_END
---------- --------- ---------
         1 01-JAN-20 04-JAN-20
         2 05-JAN-20 11-JAN-20
         3 12-JAN-20 18-JAN-20
         4 19-JAN-20 25-JAN-20
         5 26-JAN-20 01-FEB-20
         6 02-FEB-20 08-FEB-20
         7 09-FEB-20 15-FEB-20
         8 16-FEB-20 22-FEB-20
         9 23-FEB-20 29-FEB-20
        10 01-MAR-20 07-MAR-20
        11 08-MAR-20 14-MAR-20
        .......
        .......
        53 27-DEC-20 02-JAN-21

干杯!!