date_trunc postgresql code example
Example 1: date_trunc postgres
SELECT DATE_TRUNC('hour', TIMESTAMP '2017-03-17 02:09:30');
Example 2: psql datetime grather than
SELECT *
FROM table
WHERE update_date >= '2013-05-03'::date
AND update_date < ('2013-05-03'::date + '1 day'::interval);