highgo=# create table test_bb (c2 timestamp); CREATE TABLE highgo=# insert into test_bb values (to_timestamp('2018-06-05 19:55:44','yyyy-mm-dd hh24:mi:ss')); INSERT 0 1 highgo=# insert into test_bb values (to_timestamp('2018-06-05 03:55:44','yyyy-mm-dd hh24:mi:ss')); INSERT 0 1 highgo=# insert into test_bb values (to_timestamp('2018-06-05 13:55:44','yyyy-mm-dd hh24:mi:ss')); INSERT 0 1 highgo=# highgo=# highgo=# select * from test_bb; c2 --------------------- 2018-06-05 19:55:44 2018-06-05 03:55:44 2018-06-05 13:55:44 (3 rows) highgo=# select date_trunc('day',Now()); date_trunc ------------------------ 2018-06-06 00:00:00+08 (1 row) highgo=# select date_trunc('day',Now()) -interval '1d'; ?column? ------------------------ 2018-06-05 00:00:00+08 (1 row) highgo=# select date_trunc('day',Now()) -interval '1d'+interval '6 hours'; ?column? ------------------------ 2018-06-05 06:00:00+08 (1 row) highgo=# select date_trunc('day',Now())-interval '6 hours'; ?column? ------------------------ 2018-06-05 18:00:00+08 (1 row) highgo=# select * from test_bb highgo-# where (c2 > date_trunc('day',Now()) - interval '1 day' and c2 < date_trunc('day',Now()) - interval '1d' + interval '6 hours') highgo-# or (c2 > date_trunc('day',Now()) - interval '6 hours' and c2 < date_trunc('day',Now())); c2 --------------------- 2018-06-05 19:55:44 2018-06-05 03:55:44 (2 rows) highgo=# select * from test_bb; c2 --------------------- 2018-06-05 19:55:44 2018-06-05 03:55:44 2018-06-05 13:55:44 (3 rows)
如上的这个where条件就是取昨天特定时间段的sql写法。
参考:https://www.postgresql.org/docs/10/static/functions-datetime.html#FUNCTIONS-DATETIME-TRUNC