How to display the time result with 24 hour calculation - mysql

Question

For example, server time is 15:00:00. I run the following query but it gives me wrong result. Here my query
SELECT
CASE
WHEN TIME(NOW()) BETWEEN '08:00:01' AND '10:00:00'
THEN 1
WHEN TIME(NOW()) BETWEEN '14:00:01' AND '08:00:00'
THEN 2
ELSE 0
END AS IdShift
What's wrong with my query ? from that case my expected result is 2. but it give me 0

Answer 1

In a BETWEEN clause you have to specify the lower value first, then the higher value.
So you have to change BETWEEN '14:00:01' AND '08:00:00' to BETWEEN '08:00:00' AND '14:00:01'.
When you want to span from 14:00 to the next day 08:00 you have to include the date.
You could do it like this:
SELECT
CASE
WHEN NOW() BETWEEN CONCAT(CURDATE(), ' 08:00:01') AND CONCAT(CURDATE(), ' 10:00:00')
THEN 1
WHEN NOW() BETWEEN CONCAT(CURDATE(), ' 14:00:01') AND CONCAT(CURDATE() + INTERVAL 1 DAY, ' 08:00:00')
THEN 2
ELSE 0
END AS IdShift

Answer 2

As mentioned in another answer, for between the lower bound is always first. I'm not a fan of between, but you need to split your conditions:
SELECT (CASE WHEN TIME(NOW()) BETWEEN '08:00:01' AND '10:00:00'
THEN 1
WHEN TIME(NOW()) BETWEEN '14:00:01' AND '23:59:59'
THEN 2
WHEN TIME(NOW()) BETWEEN '00:00:00' AND '08:00:00'
THEN 2
ELSE 0
END) AS IdShift
Or, phrase this with or:
SELECT (CASE WHEN TIME(NOW()) > '08:00:00' AND TIME(NOW()) <= '10:00:00'
THEN 1
WHEN TIME(NOW()) > '14:00:00' OR TIME(NOW()) < '08:00:00'
THEN 2
ELSE 0
END) AS IdShift
I would be inclined to shift the logic by a minute or two and use hours:
(case when hour(now()) >= 8 and hour(now()) < 10
then 1
when hour(now()) >= 14 or hour(now()) < 8
then 2
end)