Điều này thì sao:
WITH
/* get all time points where something changes */
points AS (
SELECT "startDate" AS p
FROM temp_period
UNION SELECT "endDate"
FROM temp_period
),
/*
* Get all date ranges between these time points.
* The first time range will start with NULL,
* but that will be excluded in the next CTE anyway.
*/
inter AS (
SELECT daterange(
lag(p) OVER (ORDER BY p),
p
) i
FROM points
),
/*
* Get all date ranges that are contained
* in at least one of the intervals.
*/
overlap AS (
SELECT DISTINCT i
FROM inter
CROSS JOIN temp_period
WHERE i <@ daterange("startDate", "endDate")
)
/* sum the lengths of the date ranges */
SELECT sum(age(upper(i), lower(i)))
FROM overlap;
Đối với dữ liệu của bạn, nó sẽ trả về:
┌──────────┐
│ interval │
├──────────┤
│ 576 days │
└──────────┘
(1 row)
