Is there a predefined MySQL function that returns minimum
of its arguments' values (MINIMUM(1,16) -> 1)?
To be more specific, I have a time-on-site column in one of my mysql tables.
Every visitor polls my server every 30 sec making an update:
UPDATE `mytable` SET `lastUpdate` = NOW() WHERE `id` = ?;
but I'd like to update also timeOnSite column like this:
UPDATE `mytable` SET `timeOnSite` = (
`timeOnSite` + MINIMUM(
TIMESTAMPDIFF(SECOND, lastUpdate, NOW()), 30
)
),
`lastUpdate` = NOW() WHERE `id` = ?;
But the problem is that there are no such MINIMUM function, and I failed to find it in MySQL manuals.