PostgreSQL???????????????????

?PostgreSQL?????????????????????????????????????????????????????????

???????

PostgreSQL ??????????????????????????????????????????????????????????????????????????????????????????????

1. ??????????

???????????????????

CURRENT_DATE???????????????

CURRENT_TIME???????????????

CURRENT_TIMESTAMP???????????

CURRENT_TIME(precision)?????????????

LOCALTIME?????????????????

LOCALTIMESTAMP?????????????????????????

???????????????????????????????????

2. ??????????

???????????????????

now()????????????????????

timeofday()???????????????????

statement_timestamp()????????????????

??????????????????????????????????????

???????

??????????????????

highgo=# begin;BEGINhighgo=# select now(); now------------2023-10-18 14:22:45.678901+08:00 (1 row)highgo=# select statement_timestamp();statement_timestamp------------2023-10-18 14:22:47.890123+08:00 (1 row)

??????????? now() ? statement_timestamp() ???????????now() ????????????????? statement_timestamp() ????????????????

????????

????????????PostgreSQL ?????????????????????????

highgo=# create table t(date date);CREATE TABLEhighgo=# insert into t values (date '2023-10-18');INSERT 0 1

?????????????????????????

highgo=# insert into t values (timestamp '2023-10-18 14:22:45.678901+08:00');INSERT 0 1

???????PostgreSQL???????? ISO, MDY?????????????????????

highgo=# set datestyle = 'YMD';

???????

????????????????????????

highgo=# select time '12:09:00.123456';time---------12:09:00.123456 (1 row)

???????MySQL ????????? PostgreSQL ????????

??

? PostgreSQL ???????????????????????????????????????????????????????? CURRENT_TIMESTAMP ? LOCALTIMESTAMP?????????????????? now() ? timeofday()?

???????????????????????????????????

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