Hi all,

I've rather naively written a singleton php database class, but now realize that it simply doesn't work because php classes are not persistent, I mean, there is no memory of anything once you've downloaded a page.

So would the solution be to use a session variable ($_SESSION) to store the unique class instance? Or is there a better, classic solution? Or perhaps I should use a simple database framework.

Thanks in advance,

rm

What is your class trying to achieve?

None of the database frameworks I know of use sessions or persist in the way you're describing. Generally you take care of sessions separately from the database layer.

As kelso.b has said you need to provide more details about what you want to achieve. Normally, a singleton class within a session is sufficient, why in particular do you need a singleton across sessions? This can be done it's just that we need to understand your specific use-case.

kelso.b, graemef,

Sorry about the delay.

My application doesn't even have an interface. It is to be used with an other application which does have an interface, written in php. It is an NLP module.

It is experimental. In other words, I try things and see what happens. Sometimes, often!, I try something and because of an unending loop I have to interrupt the http request (localhost, always using the database). Because of the interruption there is often, after a while, especially when debugging, lots of db connections in progress. I know this because my Netbook slows down almost to a stand-still but when I restart MySQL, it then operates normally.

My question is also a general one: How does one go about implementing the singleton pattern in php? It just doesn't work like it does in Java or C++, for obvious reasons. And it only seems logical to me that if you only want one database connection on your machine because you only have one user, that you would use a singleton pattern. It's probably the exception to the large majority of web applications where you have to have lots of simultaneous connections.

Thanks in advance,

rm

You might want to look at persistent connections http://www.php.net/manual/en/mysqli.persistconns.php