Again on carts (and sessions)

[zazazaza]

Hi all.

I'm about to develop a new shopping basket and I'm thinking to make it with a mysql table.
The problem is that if one closes the browser the table remains dirty with items...
My (over-complicated I presume...)first idea was to write an external program which scans the table every T minutes and cleans unfinished fields.
It's possible to use session_save_handler to manage table deletion when session ends?
In this case, I have to write my own open, close, read write ecc. ecc. functions in order to use the destroy one?
In any case, in my
function destroy{....}
can I write only database stuff or I must preform other session cleanup?

Do you think it would be better storing my cart using session variables?

thanks all!

Villo

[[deleted]]

There is no function you can trigger when a session is destroyed. It would be nice to have one, but it's not needed.

Your idea about a cronjob checking for old items every X minutes is good, but it can be simpler:
just do the check every time the cart data (any cart data) is accessed.
A simple "delete from table where time>maxtime" will do.
Assuming you are not taking over Amazon's workload, this should work peachy, and saves you the crontab trouble.

If speed is an issue, you can decide not to delete the records, but to only mark them as "deleted"
then once in a while you can do a real delete and optimize on the table.

[stereo]

Actually, I had to do something similar on my page. I made an online system to tell other member when their friends were online. What happend was, when a user logged in (any user) I set their Online field (in the database) = 1. Ths meant that they were online. The only time that field got set = o was when they logged out. Also when they logged in, a timestamp was taken so I could say when the last logged in etc. This timestamp was help in a filed called LogTime.

This is where I realised that I has a problem because most of the users were logging in, and not logging out. So the system was saying that they were online when they really weren't.

This is how I over came the problem.....

header.php if a file that get's included in every document. It contains the basic structre of the page. I added this at the very top of it.......

$Time = time();

mysql_query("UPDATE Member SET Online = 0 WHERE LogTime < $Time;");

That's what I did. You can so something like this......

$Time = time();

mysql_query("DELETE FROM (table) WHERE (timestampfield) < $Time;");

Hope that will help you.

~~Stereo

[stereo]

Sorry, I got that wrong.......

It should be...

$Time = time() - 900;

mysql_query("DELETE FROM (table) WHERE (fieldname) < $Time;");

Sorry about the mix up 🙂

~~Stereo

[zazazaza]

Ok, that was the method I was thinking right now.
The problem is that by now I don't think they'll have big traffic, but I'm asked to make a package as scalable as possible and I would prefere something that won't make me saying: "buy more RAM" or something like this:=))

Surely if this is the only solution in this direction I'll choose it.

thanks all.

Villo

[Anon]

Hey, if you can solve a problem by sim;ly saying "buy more RAM" then it IS scalable! :-)