[RESOLVED] global database connection

[sophistikat]

how do i keep a global instance of a database connection?

i am creating an admin site where a form calls, checklogin.php to validate the form fields with the database. it here that i send it off to the admin.php page if everything was successful. from admin.php, I want to access the same database connection/variable.

in checklogin.php i simply have this (stripped-down version of my code)

include('../objects/db.inc');
$db = new db();

after the form is validated, i send the user over to launchAdminWebsite.php which includes 3 php files, header.php, admin.php and footer.php. From the admin.php page, I want to be able to access that $db variable again.

I tried adding the $db to my session variables but that didn't work.
I tried the serialization trick found here: http://ca2.php.net/manual/en/language.oop5.serialization.php, but that didn't work either.

so what's the best way of doing this?

[sophistikat]

i thought about closing the connection upon login and simply creating a new connection once the user gets to the admin.php page? is that too simple?

[johanafm]

Unless you create your instance inside a function or class, and do not return it from there, your db instance is global.

But global means "reachable from anywhere", not "ever-lasting". Once your script finishes execution, your database connection is destroyed and cleaned up, wether you tell PHP to close it or not.
The exception is with so called persistent connection that I've never used (and doubt I ever will), but those aren't just reused by one single user, they are actually shared among different users.

So yes, you connect to the db once per page request, and then use that connection until the script ends.

[sophistikat]

thanks. after much thought I realized that the only thing I needed from the first query was the administrators ID so i saved a copy in my session and now I am onto the next phase.