Question

How do I truncate now() to get only upto hour precision in mysql?

In

select id from Run where submitTs <= now()  and submitTs >= (now()  - interval 1 hour);

I really want the records from 12.00 PM to 1 PM instead of 12.23 PM to 1.23 PM if I am running at 1.23 PM.

So how do I say

  submitTs<= truncate_to_hour(now())

Answer 1

Try thsi query –

SELECT
  id
FROM
  Run
WHERE
  DATE(submitTs) = CURDATE() AND
  EXTRACT(HOUR FROM NOW()) = EXTRACT(HOUR FROM submitTs)

This query has better performance than first one –

SELECT
  id
FROM
  Run
WHERE
  submitTs >= CURDATE() + INTERVAL EXTRACT(HOUR FROM NOW()) HOUR AND
  submitTs < CURDATE() + INTERVAL EXTRACT(HOUR FROM NOW()) + 1 HOUR