Storing Connection references (or link identifiers) in Sessions.

mlambert

Hey guys,
I've made a Connection class that returns a variable $conn that is the link identifier for this open connection. However, when I try store this as a Session value, and then use it in another page, I am getting error messages it is telling me it is an invalid reference/link identifier. Does anyone have any idea of how I could do this?

superwormy

It is my understanding that you CANNOT store connection references at all outside of the script thats currently running. AT ALL. ie, they're all destroyed when the script ends.

mlambert

Oh really? Even if I am using a persistent connection? Is there any way around this? I was thinking of including a script that will setup my connection and then just reference a $conn variable from this script? The only problem is that I will constantly be creating Connections each time I include this script. Is there any other way I can do this?

GreyBoy

just use the persistant connection.

mlambert

I still have to pass a link identifier into the mysql_query(string query, int linkid) method. this is the problem I seem to be having.

superwormy

Storing connections would be a very bad idea. Databases usually have a connection limit, ie only 100 connections at one time.

If you stored open connections, leaving them open for each user... you could only have 100 sessions open before you need to either start deleteing sessions or changing MySQL settings to allow for more users.

Persistent connections are handled by PHP / Zend Engine for you and are the closest things to what you're asking for, use mysql_pconnect() instead of mysql_connect(). You DO NOT need to pass link identifiers for mysql_pconnect() to work, it will automatically check whether or not theres an open connection it can use.

In most tests I've done and seen done by others... mysql_pconnect() makes VERY little difference in script execution time, and in some cases just ties up connections for no reason.

ahundiak

For all intents and purposes, there is no way to pass a connection resource from one script to another. Not even with persistent connections.

The basic problem is that a web server usually handles requests by starting up a number of independent threads. Each thread maintains it's own pool of connection resources. You have no control over which thread processes which script. And thus, there is simply no way to pass connections around.

This makes it's all but impossible to, for example, create a temp table in one script and then use the temp table in a second script.