自定义拆分月份

Question

我如何将一个月一分为二？ 即 1-15 然后 15-无论是整年的剩余天数吗？ 它是这样的：

**Data**                    **Date**
some data                 01-01-2019 to 15-01-2019
some data                 16-01-2019 to 31-01-2019
some data                 01-02-2019 to 15-02-2019
some data                 16-02-2019 to 28-02-2019

等等全年或半年或一年的季度？ 我可以使用 DB2 做到这一点吗？

Answer 1

with base (date_value) as (
 values ('2020-01-01'),('2020-02-05'),('2020-03-10'),('2020-04-15'), 
        ('2020-05-05'),('2020-06-10'),('2020-07-15'),('2020-08-20'), 
        ('2020-09-11'),('2020-10-16'),('2020-11-21'),('2020-12-26') 
) 
select  
  date_value, 
  CASE 
    WHEN (day(date_value) <= 15) 
        THEN CHAR( TO_CHAR(FIRST_DAY(date_value), 'DD-MM-YYYY') || ' to ' || '15-' || LPAD(TO_CHAR(MONTH(date_value)),2, '0') || '-' || TO_CHAR(YEAR(date_value)), 30 )
      ELSE 
        CHAR( '16-' || LPAD(TO_CHAR(MONTH(date_value)),2, '0') || '-' || TO_CHAR(YEAR(date_value)) || ' to ' || TO_CHAR(LAST_DAY(date_value), 'DD-MM-YYYY') , 30) 
  END  BUCKET   
from base

最初的部分只是产生一些样本日期。

这将产生以下结果：

DATE_VALUE BUCKET
---------- ------------------------------
2020-01-01 01-01-2020 to 15-01-2020
2020-02-05 01-02-2020 to 15-02-2020
2020-03-10 01-03-2020 to 15-03-2020
2020-04-15 01-04-2020 to 15-04-2020
2020-05-05 01-05-2020 to 15-05-2020
2020-06-10 01-06-2020 to 15-06-2020
2020-07-15 01-07-2020 to 15-07-2020
2020-08-20 16-08-2020 to 31-08-2020
2020-09-11 01-09-2020 to 15-09-2020
2020-10-16 16-10-2020 to 31-10-2020
2020-11-21 16-11-2020 to 30-11-2020
2020-12-26 16-12-2020 to 31-12-2020

  12 record(s) selected.