oracle关于如何对不连续的开始结束时间进行合并

–首先通过行转列将时间区间化作月份
with tab as(
select DISTINCT CUSTOMER_CODE,SKU_CODE,
start_date + level - 1 YEAR_MONTH
from (
select rownum rn, CUSTOMER_CODE,SKU_CODE, TO_CHAR(EFFECTIVE_START_DATE, ‘YYYYMM’) start_date,
TO_CHAR(EFFECTIVE_END_DATE, ‘YYYYMM’) end_date
from (SELECT DISTINCT A.CUSTOMER_CODE,A.SKU_CODE,A.EFFECTIVE_START_DATE,
DECODE(A.EFFECTIVE_END_DATE,DATE’9999-12-31’,ADD_MONTHS(SYSDATE,12),A.EFFECTIVE_END_DATE) EFFECTIVE_END_DATE
FROM DW_DMS_D_TERRITORY_AL_TG A
WHERE TO_CHAR(NVL(A.EFFECTIVE_END_DATE,DATE’9999-12-31’),‘YYYY’) >= ‘2019’
)
)
connect by level <= end_date - start_date + 1
and prior rn = rn
and prior dbms_random.value is not null
),
tab2 as(
select * from tab
where substr(YEAR_MONTH,-2)<=12 AND substr(YEAR_MONTH,-2)<>‘00’
)
,
tab3 as(
select tab2.*,YEAR_MONTH-200000 LX
from tab2 )
,
TAB4 as(
select CUSTOMER_CODE,SKU_CODE,YEAR_MONTH,LX,ROW_NUMBER() OVER(PARTITION BY CUSTOMER_CODE,SKU_CODE ORDER BY LX)-LX PX
from TAB3
)
select CUSTOMER_CODE,SKU_CODE,
MIN(TO_DATE(YEAR_MONTH,‘yyyy-MM’)) EFFECTIVE_START_DATE,
LAST_DAY(DECODE(MAX(TO_DATE(YEAR_MONTH,‘yyyy-MM’)),TRUNC(ADD_MONTHS(SYSDATE,12),‘MM’),
DATE’9999-12-31’,MAX(TO_DATE(YEAR_MONTH,‘yyyy-MM’)))) EFFECTIVE_END_DATE
from TAB4
group by CUSTOMER_CODE,SKU_CODE,PX