从星期五开始插入每周日期

Question

我想在我的表格中插入每周日期，开始日期总是在星期五，结束日期总是在星期四。我使用此代码：

CREATE TABLE WEEK AS 
    WITH generator AS (
    SELECT DATE '2015-01-02' + LEVEL - 1 dt 
    FROM dual 
    CONNECT BY LEVEL <= DATE '2016-01-21' - DATE '2015-01-02' + 1 
      ) 
    SELECT to_char(dt, 'YYYY "SEM"IW') "KEY", 
     dt "DATE_START", 
     least(next_day(dt - 1, to_char(DATE '2015-01-08', 'DAY')), 
      last_day(dt)) "DATE_END" 
FROM generator 
WHERE to_char(dt, 'D') = to_char(DATE '2015-01-02', 'D'); 

的代码工作周在同一个月，但如果我有一个月，到下个月完成日期起始日期，有一个在没有数据插入我的表。 例如：

Date_ START | DATE_END 

29-05-2015 | 31-05-2015  
05-06-2015 | 11-05-2015 

而不是31-05-2015我应该有2015年4月6日。

Answer 1

我认为下面是你以后有什么：

with generator as (select  date '2015-05-29' + (level - 1)*7 dt 
        from  dual 
        connect by level <= (date '2016-01-21' - date '2015-05-29')/7 + 1) 
select to_char(dt, 'YYYY "SEM"IW') "KEY", 
     dt "DATE_START", 
     dt + 6 "DATE_END" 
from generator; 

KEY  DATE_START DATE_END 
---------- ---------- ---------- 
2015 SEM22 2015-05-29 2015-06-04 
2015 SEM23 2015-06-05 2015-06-11 
2015 SEM24 2015-06-12 2015-06-18 
2015 SEM25 2015-06-19 2015-06-25 
<snip> 
2016 SEM01 2016-01-08 2016-01-14 
2016 SEM02 2016-01-15 2016-01-21 

这是假设你已经在发电机子查询中指定的日期已经被确定为一个星期五。否则，您可以使用类似trunc(<date> - 4, 'iw') + 4或trunc(<date> + 3, 'iw') + 4（取决于您是否希望在指定日期包含前一个或下一个星期五）以确保种子日期肯定是星期五。

Answer 2

也许只是一个选择，你可以尝试在这里分析功能。但如Boniest所建议的 “刚加入天”会更好一些。有 乐趣

WITH generator AS 
    (SELECT DATE '2015-01-02' + LEVEL - 1 dt 
    FROM dual 
    CONNECT BY LEVEL <= DATE '2016-01-21' - DATE '2015-01-02' + 1 
) 
-- select * from generator; 
SELECT TO_CHAR(dt, 'YYYY "SEM"IW') "KEY", 
    dt "DATE_START", 
    lead(dt) over (ORDER BY (dt)) -1 "End Date" 
FROM generator 
WHERE TO_CHAR(dt, 'D') = TO_CHAR(DATE '2015-01-02', 'D'); 

----------------------------------OUTPUT----------------------------------------- 
**KEY  DATE_START End Date** 
2015 SEM18 05/01/2015 05/07/2015 
2015 SEM19 05/08/2015 05/14/2015 
2015 SEM20 05/15/2015 05/21/2015 
2015 SEM21 05/22/2015 05/28/2015 
2015 SEM22 05/29/2015 06/04/2015 

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