the singleton design pattern allows you to have one and only one instance of a class/object. it is good for large, shared resources like databases. <?php
/**
@author Brian Danchilla
@brief PDO singleton class
*/
class PDO_DBConnect {
static $db ;
private $dbh ;
private function PDO_DBConnect () {
$db_type = 'pgsql'; //ex) mysql, postgresql, oracle
$db_name = 'myDatabase';
$user = 'brian' ;
$password = 'myP@ssw0rd' ;
$host = 'localhost' ;
try {
$dsn = "$db_type:host=$host;dbname=$db_name";
$this->dbh = new PDO ( $dsn, $user, $password);
$this->dbh->setAttribute(PDO::ATTR_PERSISTENT, true);
$this->dbh->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
} catch ( PDOException $e ) {
print "Error!: " . $e->getMessage () . "\n" ;
die () ;
}
}
public static function getInstance ( ) {
if (! isset ( PDO_DBConnect::$db )) {
PDO_DBConnect::$db = new PDO_DBConnect ( ) ;
}
return PDO_DBConnect::$db->dbh;
}
}
?>
sample usage would be
$db_handle = PDO_DBConnect::getInstance();
...
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