几天来我一直在努力解决这个问题,现在我转向群众寻求帮助.
我的问题与此网站上的先前解决方案类似,但不完全相同：
PL/SQL Split, separate a date into new dates according to black out dates!
这个解决方案相当布尔(包含/排除),而我的问题涉及其中的一些以及合并.
虽然我觉得我对SQL PL / SQL有中级/高级的掌握…但Oracle Analytic函数显然让我感到困惑.我一直在努力阅读/学习,但我已经没时间了.
由于我不确定共享表名(COTS),业务线等的合法性,我将用模糊的场景/上下文来模仿我的问题.希望这能够抵御律师的精神.
关于问题：
我有一张包含客户活动历史记录的表格.客户可以来去,因此我们可能在此表中有多行(每个客户).
CREATE TABLE activity AS
SELECT 1 AS cust_id,
TO_DATE('01-JAN-2010') AS start_dt,
TO_DATE('31-JUL-2010') AS end_dt,
'EAST' AS region
FROM DUAL
UNION
SELECT 1 AS cust_id,
TO_DATE('01-FEB-2011') AS start_dt,
TO_DATE('31-DEC-2011') AS end_dt,
'EAST' AS region
FROM DUAL;
我还有一个表格,其中包含跨度的属性信息.客户可以同时拥有多个属性类型,每种类型可以多次使用不同的时间跨度.
CREATE TABLE attrib AS
SELECT 1 AS cust_id,
'POWER' AS atb_cd,
TO_DATE('01-JAN-2009') AS atb_start_dt,
TO_DATE('31-JAN-2010') AS atb_end_dt,
'LocalNuke' AS provider,
1.80 AS per_kwh,
0 AS per_gal
FROM DUAL
UNION
SELECT 1 AS cust_id,
'POWER' AS atb_cd,
TO_DATE('01-MAR-2010') AS atb_start_dt,
TO_DATE('31-MAR-2010') AS atb_end_dt,
'CoalGuys' AS provider,
1.60 AS per_kwh,
0 AS per_gal
FROM DUAL
UNION
SELECT 1 AS cust_id,
'POWER' AS atb_cd,
TO_DATE('01-JUN-2010') AS atb_start_dt,
TO_DATE('30-SEP-2010') AS atb_end_dt,
'LocalNuke' AS provider,
1.70 AS per_kwh,
0 AS per_gal
FROM DUAL
UNION
SELECT 1 AS cust_id,
'POWER' AS atb_cd,
TO_DATE('01-MAR-2011') AS atb_start_dt,
TO_DATE('31-DEC-9999') AS atb_end_dt,
'GeoHeat' AS provider,
1.10 AS per_kwh,
0 AS per_gal
FROM DUAL
UNION
SELECT 1 AS cust_id,
'WATER' AS atb_cd,
TO_DATE('01-MAR-2010') AS atb_start_dt,
TO_DATE('31-DEC-9999') AS atb_end_dt,
'GlacialGold' AS provider,
0 AS per_kwh,
0.60 AS per_gal
FROM DUAL;
数据奇怪是有意的,我试图将这个场景尽可能地变为现实世界而不与“现实世界”相关.
结果应该限制客户与这家虚构公司的活动的跨度,并将所有重叠日期分开以形成时间表.需要将数据元素合并在一起以进行报告.
视觉：
Cust:
|----------------------| |------------------------|
Power:
|-------------| |--| |-------| |---------------------->
Water:
|------------------------------------------------------>
Expected Result:
|----|----|--|----|----| |----|-------------------|
解决方案应该是可扩展的,以包括其他属性.最后,我在表格中有这种非规范化信息,这样我就可以在任何时间点报告客户的数据.例如,如果他们在某一天有活动,权力和水;我应该能够导出当天的per_kwh,per_gal和活动数据.
示例输出(表格)：
CUST_ID FROM_DT THRU_DT REGION POWER_PROVIDER WATER_PROVIDER PER_KWH PER_GAL
------- ----------- ----------- ------ -------------- -------------- ------- -------
1 01-JAN-2010 31-JAN-2010 EAST LocalNuke 1.80 0
1 01-FEB-2010 28-FEB-2010 EAST 0 0
1 01-MAR-2010 31-MAR-2010 EAST CoalGuys GlacialGold 1.60 0.60
1 01-APR-2010 31-MAY-2010 EAST GlacialGold 0 0.60
1 01-JUN-2010 31-JUL-2010 EAST LocalNuke GlacialGold 1.70 0.60
1 01-FEB-2011 28-FEB-2011 EAST GlacialGold 0 0.60
1 01-MAR-2011 31-DEC-2011 EAST GeoHeat GlacialGold 1.10 0.60
我在2年前写了一些东西(当需求类似于Activity / Power时),使用2个异步游标逐慢处理(逐行).
虽然性能很重要,但我试图找到直接/批量sql解决方案的最大原因是维护.我的原始解决方案的if / else光标嵌套已经难以遵循,并且至少还有2个“属性”跨度要分裂,指数会更糟.
如果您能提供任何帮助,我将不胜感激.
最佳答案 这可能有效.它不会将连续的区域合并在一起,但它仍然应该完成工作.
WITH
milestone AS
(
SELECT cust_id, start_dt AS point_in_time FROM ACTIVITY
UNION
SELECT cust_id, atb_start_dt AS point_in_time FROM ATTRIB
UNION
SELECT cust_id, LEAST(end_dt, TO_DATE('30-DEC-9999')) + 1 AS point_in_time FROM ACTIVITY
UNION
SELECT cust_id, LEAST(atb_end_dt, TO_DATE('30-DEC-9999')) + 1 AS point_in_time FROM ATTRIB
)
SELECT
milestone.cust_id AS cust_id,
milestone.point_in_time AS from_dt,
LEAD(point_in_time)
OVER (PARTITION BY milestone.cust_id ORDER BY milestone.point_in_time) - 1
AS thru_dt,
activity.region AS region,
power_attrib.provider AS power_provider,
water_attrib.provider AS water_provider,
COALESCE(power_attrib.per_kwh, 0) AS per_kwh,
COALESCE(water_attrib.per_gal, 0) AS per_gal
FROM
MILESTONE
LEFT OUTER JOIN ACTIVITY
ON milestone.cust_id = activity.cust_id
AND milestone.point_in_time BETWEEN activity.start_dt AND activity.end_dt
LEFT OUTER JOIN ATTRIB power_attrib
ON milestone.cust_id = power_attrib.cust_id
AND power_attrib.atb_cd = 'POWER'
AND milestone.point_in_time BETWEEN power_attrib.atb_start_dt AND power_attrib.atb_end_dt
LEFT OUTER JOIN ATTRIB water_attrib
ON milestone.cust_id = water_attrib.cust_id
AND water_attrib.atb_cd = 'WATER'
AND milestone.point_in_time BETWEEN water_attrib.atb_start_dt AND water_attrib.atb_end_dt
