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Fortern
2025-11-03 05:49:10 +08:00
parent bb902c36fc
commit afaa00c056
1 changed files with 6 additions and 6 deletions
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PostgreSQL/time.sql
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@@ -1,10 +1,10 @@
-- 设置会话时区 -- 设置会话时区
SET TIME ZONE 'Asia/Shanghai'; SET TIME ZONE 'Asia/Shanghai';
-- msg_time 是 timestamptz类型 -- AT TIME ZONE 在 PostgreSQL 中是重载的，行为取决于左侧的类型：
select msg_time from msg where id = 1; -- timestamp WITHOUT time zone AT TIME ZONE zone → 把该 wall time 视为 zone 的本地时间，然后转换为 UTC，结果为 timestamptz（显示为 UTC 偏移后的时间）。
select msg_time AT TIME ZONE 'Asia/Shanghai' from msg where id = 1; -- timestamptz AT TIME ZONE zone → 把该瞬间转换成 zone 的本地 wall time，结果为 timestamp WITHOUT time zone。
select msg_time AT TIME ZONE 'UTC+8' from msg where id = 1; select msg_time at time zone 'Asia/Shanghai' from msg where id = 1;
select msg_time at time zone 'UTC+8' from msg where id = 1;
SELECT to_timestamp(1761850339); select to_timestamp(1761850339) AT TIME ZONE 'Asia/Shanghai';
SELECT to_timestamp(1761850339) AT TIME ZONE 'Asia/Shanghai';