<!-- Collection of code snippets by Arne Vajhøj -->
<!-- (from articles on eksperten.dk / vajhoej.dk written sometime between 2004 and now) -->
<?php

require 'DB.php';

class StandardTransaction extends DB {
	public function getConnection() {
		$con = new PDO('mysql:host=localhost;dbname=Test', 'root', 'hemmeligt');
		$con->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
		$con->setAttribute(PDO::ATTR_DEFAULT_FETCH_MODE, PDO::FETCH_ASSOC);
		return $con;
	}
	public function test() {
		for($i = 0; $i < 10; $i++) {
			$con = $this->getConnection();
			$con->beginTransaction();
			try {
				$con->query("UPDATE tblsrc SET val = val - 1 WHERE id = 1");
				if($i % 2 != 0) throw new Problem();
				$con->query("UPDATE tbltrg SET val = val + 1 WHERE id = 1");
				$con->commit();
			} catch(Problem $ex) {
				$con->rollback();
				echo "Problem\r\n";
			}
		}
	}
}

DB::demo(new StandardTransaction());

?>