Discard millisecond part from timestamp

Solution 1:

A cast to timestamp(0) or timestamptz(0) rounds to full seconds:

SELECT now()::timestamp(0);

Fractions are not stored in table columns of this type.

date_trunc() truncates (leaves seconds unchanged) - which is often what you really want:

SELECT date_trunc('second', now()::timestamp);

Discard milliseconds:

SELECT DATE_TRUNC('second', CURRENT_TIMESTAMP::timestamp);

2019-08-23 16:42:43

Discard seconds:

SELECT DATE_TRUNC('minute', CURRENT_TIMESTAMP::timestamp);

2019-08-23 16:42:00