在评论中澄清后。
我理解的你的任务：
检查所有提供的单个日期范围 (filter) 是否包含在表中代码集的组合日期范围内 (invoice )。
可以使用普通的 SQL 来完成，但它不是一项简单的任务。步骤可能是：
-
提供日期范围作为过滤器。
-
按代码组合invoice 表中的日期范围。
每个代码可以产生一个或多个范围。
-
查找过滤器和合并发票之间的重叠
-
分类：完全覆盖/部分覆盖。
可能导致一项全覆盖、一或两个部分覆盖或不覆盖。
减少到最大覆盖范围。
-
以合理的排序顺序为（过滤器、代码）的每个组合以及结果覆盖率显示一行
临时过滤器范围
WITH filter(filter_id, startdate, enddate) AS (
VALUES
(1, '2012-05-01'::date, '2012-06-05'::date) -- list filters here.
,(2, '2012-05-01', '2012-05-31')
,(3, '2012-06-01', '2012-06-30')
)
SELECT * FROM filter;
或者将它们放在一个（临时）表中，然后使用该表。
按代码组合重叠/相邻的日期范围
WITH a AS (
SELECT code, startdate, enddate
,max(enddate) OVER (PARTITION BY code ORDER BY startdate) AS max_end
-- Calculate the cumulative maximum end of the ranges sorted by start
FROM invoice
), b AS (
SELECT *
,CASE WHEN lag(max_end) OVER (PARTITION BY code
ORDER BY startdate) + 2 > startdate
-- Compare to the cumulative maximum end of the last row.
-- Only if there is a gap, start a new group. Therefore the + 2.
THEN 0 ELSE 1 END AS step
FROM a
), c AS (
SELECT code, startdate, enddate, max_end
,sum(step) OVER (PARTITION BY code ORDER BY startdate) AS grp
-- Members of the same date range end up in the same grp
-- If there is a gap, the grp number is incremented one step
FROM b
)
SELECT code, grp
,min(startdate) AS startdate
,max(enddate) AS enddate
FROM c
GROUP BY 1, 2
ORDER BY 1, 2
另一种最终选择（可能更快，也可能更快，您必须进行测试）：
SELECT DISTINCT code, grp
,first_value(startdate) OVER w AS startdate
,last_value(enddate) OVER w AS enddate
FROM c
WINDOW W AS (PARTITION BY code, grp ORDER BY startdate
RANGE BETWEEN UNBOUNDED PRECEDING AND UNBOUNDED FOLLOWING)
ORDER BY 1, 2;
合并到一个查询
WITH
-- supply one or more filter values
filter(filter_id, startdate, enddate) AS (
VALUES
(1, '2012-05-01'::date, '2012-06-05'::date) -- cast values in first row
,(2, '2012-05-01', '2012-05-31')
,(3, '2012-06-01', '2012-06-30')
)
-- combine date ranges per code
,a AS (
SELECT code, startdate, enddate
,max(enddate) OVER (PARTITION BY code ORDER BY startdate) AS max_end
FROM invoice
), b AS (
SELECT *
,CASE WHEN (lag(max_end) OVER (PARTITION BY code ORDER BY startdate)
+ 2) > startdate THEN 0 ELSE 1 END AS step
FROM a
), c AS (
SELECT code, startdate, enddate, max_end
,sum(step) OVER (PARTITION BY code ORDER BY startdate) AS grp
FROM b
), i AS ( -- substitutes original invoice table
SELECT code, grp
,min(startdate) AS startdate
,max(enddate) AS enddate
FROM c
GROUP BY 1, 2
)
-- match filters
, x AS (
SELECT f.filter_id, i.code
,bool_or(f.startdate >= i.startdate
AND f.enddate <= i.enddate) AS full_cover
FROM filter f
JOIN i ON i.enddate >= f.startdate
AND i.startdate <= f.enddate -- only overlapping
GROUP BY 1,2
)
SELECT f.*, i.code
,CASE x.full_cover
WHEN TRUE THEN 'fully covered'
WHEN FALSE THEN 'partially covered'
ELSE 'invoice missing'
END AS covered
FROM (SELECT DISTINCT code FROM i) i
CROSS JOIN filter f -- all combinations of filter and code
LEFT JOIN x USING (filter_id, code) -- join in overlapping
ORDER BY filter_id, code;
在 PostgreSQL 9.1 上测试并为我工作。