MySQL时间戳从创建时起30天有效期

Question

What I am trying to do here is adding an 30 DAYS to the timestamp when the session key was created.

SELECT * FROM `sessions` 
WHERE (`timestamp` + INTERVAL 30 DAY) <= UTC_TIMESTAMP()

And then checking it to the current time.

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But this doesn't work because the session was created just a few days ago. So the timestamp is way larger than UTC_TIMESTAMP (the current time).

I can ADD another condition AND (timestamp + INTERVAL 30 DAY) >= UTC_TIMESTAMP(), but I would have to calculate the interval again.

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Is there a more efficient way to have this done?

Answer 1

Try this instead:

`timestamp` >= DATE_SUB(NOW(), INTERVAL 30 DAY)