PHP – Simple PDO Class for Connecting to a MySQL Database

Here’s an extremely basic, reusable PHP and MySQL based PDO class for easily connecting to multiple database servers simultaneously within a script without having to go through a bunch of hoopla. Tidbits have been pieced together from the following sources with a little tweaking of my own (such as the ability to have default database values or to pass them as arguments):
http://simple_pdo_implementation.onlinephpfunctions.com/
http://culttt.com/2012/10/01/roll-your-own-pdo-php-class/
http://code.tutsplus.com/tutorials/why-you-should-be-using-phps-pdo-for-database-access–net-12059

<?php
// Simple PDO class for connecting to MySQL DB
class sql {
	public static $db = false;
	// Here you can set some defaults if no arguments are supplied when calling the class
	private $DBHOST = '127.0.0.1';
	private $DBUSER = 'johndoe';
	private $DBPASS = 'secret';
	private $DBNAME = 'somedb';
	private $OPTIONS = array(
		PDO::MYSQL_ATTR_INIT_COMMAND => 'SET NAMES \'UTF8\'',
		PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION
	);

	public function __construct($dbhost = null, $dbname = null, $dbuser = null, $dbpass = null, $options = null) {
	// Any options passed as arguments here should be in array format as above
	// If you wanted to set attributes after being connected, use the setPDOAttrib function
		if (self::$db === false) {
			$dsn = "mysql:host=" . (isset($dbhost) ? $dbhost : $this->DBHOST) . ";dbname=" . (isset($dbname) ? $dbname : $this->DBNAME);
			try {
				$this->db = new PDO($dsn, (isset($dbuser) ? $dbuser : $this->DBUSER), (isset($dbpass) ? $dbpass : $this->DBPASS), (isset($options) ? $options : $this->OPTIONS));
			} catch (PDOException $e) {
				print $e->getMessage();
			}
		}
	}

	public function setPDOAttrib(){
	// Can handle multiple arguments but the parameters passed here should be
	// sent as one big string wrapped in quotes and separated by commas as below
	// "PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION", "PDO::blah, PDO::blarg"
		foreach(func_get_args() as $arg) {
			if (($this->getStatus() == "1") && (!is_null($arg))) {
				try {
					$this->db->setAttribute($arg);
				} catch (PDOException $e) {
					print $e->getMessage();
				}
			}
		}
	}
	
	public function getStatus() {
		if ($this->db === true)	{
			return 1;
		} else {
			return 0;
		}
	}
	
	public function close() {
		if ($this->getStatus() == "1") {
			$this->db = null;
		}
	}
} 
?>

And you can call on the class like this:

$var = new sql ("localhost", "mysqluser", "mysqlpass", "mydb");
$sth = $var->db->prepare(
	"SELECT
		*
	FROM
		`sometable`
	WHERE
		`someid` = ?
	AND
		`somefield` = ?
	");
$sth->execute( array ('2402', 'candyland') );
while( $r = $sth->fetchAll() ) {
	echo $r;
}

Or to fetch an associative array you can use:

while($r = $sth->fetch(PDO::FETCH_ASSOC)) {
	echo "$r[someid]</br>";
	echo "$r[somefield]</br>";
}

Last but not least, close your connection by doing this:

$var->close();