假设您有以下PostgreSQL稀疏表,列出了预订日期:
CREATE TABLE reserved_dates (
reserved_days_id SERIAL NOT NULL,
reserved_date DATE NOT NULL
);
INSERT INTO reserved_dates (reserved_date) VALUES
('2014-10-11'),
('2014-10-12'),
('2014-10-13'),
-- gap
('2014-10-15'),
('2014-10-16'),
-- gap
('2014-10-18'),
-- gap
('2014-10-20'),
('2014-10-21');
你如何将这些日期聚合为连续的日期范围(没有间隙的范围)?例如:
start_date | end_date
------------+------------
2014-10-11 | 2014-10-13
2014-10-15 | 2014-10-16
2014-10-18 | 2014-10-18
2014-10-20 | 2014-10-21
这是我目前想到的,但我只能以这种方式获取start_date
:
WITH reserved_date_ranges AS (
SELECT reserved_date,
reserved_date
- LAG(reserved_date) OVER (ORDER BY reserved_date) AS difference
FROM reserved_dates
)
SELECT *
FROM reserved_date_ranges
WHERE difference > 1 OR difference IS NULL;