Question

I have a custom database class that I wrote myself, and I also have a user class and a site class.

The MySQL class has methods like this:

connect
query
clean
fetch

The user class:

register
login
logout
resetPass

The site class:

updateTopics
addTopic
addPost
addReply

etc.

These classes need to interface with a database, which is what I wrote the MySQL class for. But, I have no idea how to properly use the MySQL class with these classes. Do I define the class as global and just reference it in the other classes? Do I do something like:

$db = new MySQL();
$user = new User($db);

and then reference it like that?

Any help is appreciated, thank you. 🙂

Answer 1

In addition to Daniel Vandersluis’s answer:
Instantiating the object within your class creates a strong dependency between those classes. You might instead be interested in dependency injection and inversion of control (+ ioc containers).

see:
http://en.wikipedia.org/wiki/Dependency_injection
http://martinfowler.com/articles/injection.html

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btw: Do you really need your own MySQL class implementation? There are already so many database access and abstraction layers available. E.g. http://docs.php.net/pdo.