login user only one device at a time

[suraj]

i want to create a login script that user can login one device at one time if user login from new device the old login device will logout automatcally using php

[ginerjm]

Suggestion.  When a user logs in successfully post a record of it in a separate table, say 'active_users'.  Then when they try and login again, check if they are already active (in that table), and if so, delete them and continue on to the normal login process.

Your 'active_users' table may need a datetime value in it that allows for a record to expire and be automatically cleaned up by a separate process, perhaps a cron job that runs once a day or something.

[requinix]

Use regular sessions, so a session on each device, then associate the session ID with the user record. If it doesn't match on a page load then log the user out.

[ginerjm]

Very clever.  Didnt' think that far along.  

@Suraj - scratch my idea!

[schwim]

If you want a more persistent login than solely relying on PHP sessions, save a random token to the db and store it in a cookie.  If the user shows up in a different PHP session, check the token against the latest active stored in the db.  If they differ, scrap all logins for that user and point them towards the login.