Database PDO wrapper class for PHP

db_pdo_class.php

<?php
/**
 * Database PDO Wrapper
*/
if (!class_exists('Database')) {

	// Define configuration
	define("DB_HOST", "localhost");
	define("DB_USER", "username");
	define("DB_PASS", "pass");
	define("DB_NAME", "dbname");
	
	class Database extends PDO {
		
		private $host      = DB_HOST;
		private $user      = DB_USER;
		private $pass      = DB_PASS;
		private $dbname    = DB_NAME;

		private $dbh;
		private $error;

		private $stmt;
	 
	    public function __construct($dbuser = "", $dbpass = "") {
	    	  if (!empty($dbuser)) { $this->user = $dbuser; }
	    	  if (!empty($dbpass)) { $this->pass = $dbpass; }

	        // Set DSN
	        $dsn = 'mysql:host=' . $this->host . ';dbname=' . $this->dbname;
        
	        // Set options
	        $options = array(
	            PDO::ATTR_PERSISTENT    => true,
	            PDO::ATTR_ERRMODE       => PDO::ERRMODE_EXCEPTION
	        );
        
	        // Create a new PDO instanace
	        try {
	            $this->dbh = new PDO($dsn, $this->user, $this->pass, $options);
	            $this->dbh->exec("SET NAMES 'utf8'");
	        }
	        // Catch any errors
	        catch (PDOException $e) {
	            $this->error = $e->getMessage();
	        }
	    }
		
		
		// Prepare
		public function query($query) {
			$this->stmt = $this->dbh->prepare($query);
		}
		
		// Bind
		public function bind($param, $value, $type = null) {
			if (is_null($type)) {
				switch (true) {
					case is_int($value):
						$type = PDO::PARAM_INT;
						break;
					case is_bool($value):
						$type = PDO::PARAM_BOOL;
						break;
					case is_null($value):
						$type = PDO::PARAM_NULL;
						break;
					default:
						$type = PDO::PARAM_STR;
				}
			}
			$this->stmt->bindValue($param, $value, $type);
		}
		
		// Execute
		public function execute() {
			return $this->stmt->execute();
		}
		
		// Result Set	
		public function resultset($fetchType = PDO::FETCH_ASSOC) {
			$this->execute();
			return $this->stmt->fetchAll($fetchType);
		}
		
		// Single
		public function single($fetchType = PDO::FETCH_ASSOC) {
			$this->execute();
			return $this->stmt->fetch($fetchType);
		}
		
		// Row Count
		public function rowCount() {
			return $this->stmt->rowCount();
		}
		
		// Last Insert Id
		public function lastInsertId($seqname = NULL) {
			return $this->dbh->lastInsertId($seqname);
		}
		

		// Transactions
		public function beginTransaction() {
			return $this->dbh->beginTransaction();
		}
		
		public function endTransaction() {
			return $this->dbh->commit();
		}
		
		public function cancelTransaction() {
			return $this->dbh->rollBack();
		}
		
		// Debug Dump Parameters
		public function debugDumpParams() {
			return $this->stmt->debugDumpParams();
		}
	}
}