PHP会话ID - SID有效多长时间？ [重复]

Question

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• How do I expire a PHP session after 30 minutes? 13 answers

Theoretically, if a PHP session ID is stored in a cookie that has a lifetime of 365 days, will the session ID resume the right session data on day 365 or will the related session data be timed out/deleted due to the session lifetime settings?

And how long can/should I store and use a session ID?

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Answer 1

In theory you can store it as long as you want, but you will be needlessly using up resources. The default is 20 minutes and can be adjusted in php.ini by setting the session.gc_maxlifetime parameter. If you need to persist data for longer than that, it would make sense to put it into a database rather than the session.