sql - 比较随时间戳变化的字符

Question

我正在尝试比较与 postgresSQL 中的时间戳不同的字符。

我想获取当前时间之前的所有值与字符变化时间戳相比。

这会正确比较吗？

WHERE to_timestamp('2018-12-25T06:00:00+01:00', 'YYYY-MM-DD HH24:MI:SS') < now()

Answer 1

不完全是。文字中有应该解析的时区值。相比：

select
    to_timestamp('2018-12-25T06:00:00+01:00', 'YYYY-MM-DD HH24:MI:SS') as "seems ok",
    to_timestamp('2018-12-25T07:00:00+02:00', 'YYYY-MM-DD HH24:MI:SS') as "but this is wrong!",
    to_timestamp('2018-12-25T06:00:00+01:00', 'YYYY-MM-DD HH24:MI:SS+TZH:TZM') as "ok",
    to_timestamp('2018-12-25T07:00:00+02:00', 'YYYY-MM-DD HH24:MI:SS+TZH:TZM') as "ok too"

        seems ok        |   but this is wrong!   |           ok           |         ok too         
------------------------+------------------------+------------------------+------------------------
 2018-12-25 06:00:00+01 | 2018-12-25 07:00:00+01 | 2018-12-25 06:00:00+01 | 2018-12-25 06:00:00+01
(1 row)