using a db class

[ps2gamer]

This is code from invision powerboard:

//--------------------------------
// Load the DB driver and such
//--------------------------------

$INFO['sql_driver'] = !$INFO['sql_driver'] ? 'mySQL' : $INFO['sql_driver'];

$to_require = ROOT_PATH."sources/Drivers/".$INFO['sql_driver'].".php";
require ($to_require);

$DB = new db_driver;

$DB->obj['sql_database']     = $INFO['sql_database'];
$DB->obj['sql_user']         = $INFO['sql_user'];
$DB->obj['sql_pass']         = $INFO['sql_pass'];
$DB->obj['sql_host']         = $INFO['sql_host'];
$DB->obj['sql_tbl_prefix']   = $INFO['sql_tbl_prefix'];

$DB->obj['debug']            = ($INFO['sql_debug'] == 1) ? $_GET['debug'] : 0;

// Get a DB connection

$DB->connect();

and once it does that in an include file or something you can do SQL queries w/ ease. like:

$DB->query("SELECT id, name, mgroup, password, ip_address FROM ibf_members WHERE LOWER(name)='$username'");

my question is:
What is that db_driver?

and what on earth does this line do:

$INFO['sql_driver'] = !$INFO['sql_driver'] ? 'mySQL' : $INFO['sql_driver'];

im trying to get my own class setup to do sql queries, but im not sure whats required and whats not? Can anyone help me make a class like this?

[drew010]

db_driver is the name of the class that does the database connections and queries etc...

and
$INFO['sql_driver'] = !$INFO['sql_driver'] ? 'mySQL' : $INFO['sql_driver'];
is exactly the same as

if (!$INFO['sql_driver']) {
    $INFO['sql_driver'] = 'mySQL';
} else {
    $INFO['sql_driver'] = $INFO['sql_driver'];
}

the ? : is called the ternary operator.
http://php.net/manual/en/language.operators.comparison.php

if you are using mysql, you will want to include the file sources/Drivers/mysql.php
that probably contains the class declaration. so you can look in there for class db_driver.

[ps2gamer]

Thanks drew, it cleared up all my questions