--function to get random number============================================================= -- DROP FUNCTION IF EXISTS get_random_number(integer, integer); CREATE OR REPLACE FUNCTION get_random_number(integer, integer) RETURNS integer AS $BODY$ DECLARE start_int ALIAS FOR $1; end_int ALIAS FOR $2; BEGIN RETURN trunc(random() * (end_int-start_int + 1) + start_int); END; $BODY$ LANGUAGE plpgsql; --產生1-10之間的隨機數(包括邊緣) --SELECT get_random_number(1, 10); --function for get random date between start_date and end_date -- DROP FUNCTION IF EXISTS get_random_date(date, date); CREATE OR REPLACE FUNCTION get_random_date(start_date date, end_date date) RETURNS timestamp AS $BODY$ DECLARE interval_days integer; random_days integer; random_date date; BEGIN interval_days := end_date - start_date; random_days := get_random_number(0, interval_days); random_date := start_date + random_days; --RETURN date_part('year', random_date) * 10000 + date_part('month', random_date) * 100 + date_part('day', random_date); RETURN to_timestamp(date_part('year', random_date)||'-'||date_part('month', random_date)||'-'||date_part('day', random_date)||' 13:12:12','YYYY-MM-DD HH24:MI:SS'); --SELECT to_timestamp('2015'||'-'||'12'||'-'||'22'||' 13:12:12','YYYY-MM-DD HH24:MI:SS') END; $BODY$ LANGUAGE plpgsql;