如何将日期时间列start_at
转换为星期几并找出相对于当前日期的下一个事件?
我在这里尝试将DOW添加到本周,但它看起来并不正确。
SELECT date_trunc('week', current_date) + CAST(extract(dow from start_at) || ' days' AS interval)
完整示例:
SELECT id event_id,
GENERATE_SERIES(date_trunc('week', current_date) + CAST(extract(dow from start_at) + 1 || ' days' AS interval) + start_at::time, current_date + interval '3 weeks', '1 week'::INTERVAL) AS start_at
FROM events
+-----+---------------------------+---------------------+
| id | start_at | recurring_schedule |
+-----+---------------------------+---------------------+
| 358 | 2015-01-23 20:00:00 +0000 | Weekly |
| 359 | 2016-01-22 19:30:00 +1100 | Monthly |
| 360 | 2016-02-01 19:00:00 +1100 | Weekly |
| 361 | 2016-02-01 20:00:00 +0000 | Weekly |
| 362 | 2014-02-13 20:00:00 +0000 | Bi-Weekly |
+-----+---------------------------+---------------------+
+----------+---------------------------+
| event_id | start_at |
+----------+---------------------------+
| 35 | 2018-04-11 19:30:00 +0000 |
| 94 | 2018-04-12 20:00:00 +0100 |
| 269 | 2018-04-13 18:30:00 +0100 |
| 45 | 2018-04-13 20:00:00 +0100 |
| 242 | 2018-04-13 19:30:00 +1100 |
| 35 | 2018-04-18 19:30:00 +0000 |
| 94 | 2018-04-19 20:00:00 +0100 |
| 269 | 2018-04-20 18:30:00 +0100 |
| 45 | 2018-04-20 20:00:00 +0100 |
| 242 | 2018-04-20 19:30:00 +1100 |
+----------+---------------------------+
答案 0 :(得分:1)
尝试一下:
SELECT id event_id,
GENERATE_SERIES(date_trunc('week', current_date)::date
+ (extract(isodow from start_at)::int - 1) + start_at::time, current_date
+ interval '3 weeks', '1 week'::INTERVAL) AS start_at
FROM events