postgresql - Postgres 时间 00 和 24 小时

Question

为什么下面的查询返回 false ?

SELECT ('00:00:00'::TIME) = ('24:00:00'::TIME) AS "time", ('00:00:00'::TIMETZ) = ('24:00:00'::TIMETZ) AS "timetz"

结果:

+-------+--------+
| time  | timetz |
+-------+--------+
| false | false  |
+-------+--------+

虽然以下查询的结果是一样的!!

SELECT ('00:00:00'::TIME) AS "time1", ('24:00:00'::TIME) AS "time2", ('00:00:00'::TIMETZ) AS "timetz1" , ('24:00:00'::TIMETZ) AS "timetz2"

结果:

+----------+----------+------------------------+------------------------+
|  time1   |  time2   |        timetz1         |        timetz2         |
+----------+----------+------------------------+------------------------+
| 00:00:00 | 00:00:00 | 00:00:00.000000 +00:00 | 00:00:00.000000 +00:00 |
+----------+----------+------------------------+------------------------+

00:00:00 和有什么区别和 24:00:00在 postgres 中？

Answer 1

Postgres' time类型定义为范围为 '00:00:00'至 '24:00:00' ，包括两端。要了解两个端点为何不同，请考虑:

SELECT '00:00:00'::time AS start, '24:00:00'::time AS end;

对于最终值，我看到 1.00:00:00 ，与您所看到的相反，表明 24 小时实际上是一天，时、分和秒为零。