tsrange计算时间间隔？

Question

我有一个 table 房间预订：

CREATE TABLE reservation (room int, during tsrange);
INSERT INTO reservation VALUES
    (1108, '[2010-01-01 09:30, 2010-01-01 10:30)');

问题：

我需要获取此房间的剩余空闲时间间隔：白天 30 分钟、45 分钟、1 小时 1.30 分钟 (09.00 - 18.00)。怎么做？感谢大家。

Answer 1

以下查询将return reservation 中有条目的所有日期的所有空闲间隔：

WITH mins(lt) AS (
   /* get all lower bounds of intervals */
   SELECT lower(during)
   FROM reservation
   UNION
   /* get 18:00 for each day */
   SELECT date_trunc('day', lower(during)) + INTERVAL '18 hours'
   FROM reservation
), maxs(ut) AS (
   /* get all upper bounds of intervals */
   SELECT upper(during)
   FROM reservation
   UNION
   /* get 09:00 for each day */
   SELECT date_trunc('day', lower(during)) + INTERVAL '9 hours'
   FROM reservation
)
SELECT tsrange(ut, lt)  /* candidate for a free interval */
FROM mins
   JOIN maxs
      ON date_trunc('day', lt) = date_trunc('day', ut)
         AND ut < lt
/* exclude all such intervals that overlap an entry */
WHERE NOT EXISTS (SELECT 1 FROM reservation
                  WHERE during && tsrange(ut, lt, '()'))
ORDER BY ut;

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tsrange计算时间间隔？

Tsrange calculation of time intervals?

sql

postgresql

date-range