Session related issues

Session question
Encountered a strange problem,
Session processing. I used a database, but the problem came.
User login information has not been saved, after tracking, found multiple calls to Session_write (), the database into the SQL only the first time the data is right. Then use the files store without using database storage. The problem is gone. There seems to be a problem with the script that handles the session, but the local test is good. There is only a problem on the line. Control Phpinfo played session information, did not find anything different. What's the situation?

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The key to see how you write to the database AH. You should not have updated the nearest session.
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There was a problem writing to the database.
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Session_write should be judged whether the corresponding session_id exists
If present, execute modify update
Otherwise, insert inserts are executed
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Explore

Reference:

Session_write should be judged whether the corresponding session_id exists
If present, execute modify update
Otherwise, insert inserts are executed


There are no multiple insertions or updates in the local test.

Thank you for your help.

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