Generating a Random Date

[Deleted User]

This blog post was authored by Jim Knicely.

I can easily generate a random integer value using the Vertica built-in RANDOMINT function.

For example:

dbadmin=> SELECT randomint(10) "Random 0-9",
dbadmin->        randomint(10) "Random 0-9",
dbadmin->        randomint(10) "Random 0-9";
Random 0-9 | Random 0-9 | Random 0-9
------------+------------+------------
          6 |          4 |          0
(1 row)

But what if I need a random date? Luckily in Vertica I can create my own SQL function for that!

Example

dbadmin => CREATE OR REPLACE FUNCTION randomdate (d1 TIMESTAMP, d2 TIMESTAMP) RETURN TIMESTAMP
dbadmin -> AS
dbadmin -> BEGIN
dbadmin ->   RETURN TO_TIMESTAMP(EXTRACT(EPOCH FROM d1) + RANDOMINT(FLOOR(EXTRACT(EPOCH FROM d2) - EXTRACT(EPOCH FROM d1))::INT));
dbadmin -> END;
CREATE FUNCTION
dbadmin => SELECT randomdate('2018-01-01', '2018-12-31') randomdate_in_2018, randomdate(sysdate-30, sysdate) randomdate_last_30_days;
randomdate_in_2018  |  randomdate_last_30_days
---------------------+----------------------------
2018-04-16 04:28:37 | 2018-01-08 12:41:14.810584
(1 row)