php commit bug

<?
/* contact: cottton (@i-stats.net or ts3:i-stats.net)
EXPLANATION:
    using PDO to fire more than 1 "INSERT INTO" via PDO::beginTransaction() and PDO::commit()
    Q: what does it mean?
    A: this means i try to send more than 1 query to the mysql server at once:

    $dbh->beginTransaction();
    $sql = "
       INSERT INTO `testdb`.`tbl` SET `name` = 'a';
       INSERT INTO `testdb`.`tbl` SET `name` = 'b';
       INSERT INTO `testdb`.`tbl` SET `name` = 'c';
    ";
    $stmt = $dbh->prepare($sql);
    $stmt->execute();
    $dbh->commit();

    Q: does this work?
    A: no. somehow the mysql server still waits for the commit.


THE TEST SCRIPT:
    Q: is it 10 to 20 lines?
    A: no. hell! i cant write you that test script in 20 lines.

    explanation:
    there are 2 ways we will fire this multi-query:
    1. regular as above
    2. a alternative way: we "destroy" the $stmt before we fire the ->commit()

    Q: how do i use this test script?
    A: just adapt the settings:
        $mysql_username, $mysql_password, $mysql_host and the $type

    Q: for what is the $type for?
    A: it allows you to switch between the 2 ways we use to fire the multi-query.
        so you will first look at the regular way to see that the multi-inserts didnt work,
        and then switch to the alternative way to see that they surprisingly worked.
    (!) please be sure you truncated the table after using the alternative way
        i wont do that for you ...

    Q: how do i see the result?
    A: in your browser =)

you dont really have to read the script.
the output shows you what happen.
so here is the script:
(and this is the last time ill try to explain you that bug, sorry but ...)
*/

# db settings:
$mysql_username = 'username';
$mysql_password = 'password';
$mysql_host     = 'localhost';

# switch here the $type (un-/comment one of those):
$type = 'regular'; # regular way
#$type = 'alternative'; # alternative way


echo '<h1>using PDO to insert multi-querys using beginTransaction() and commit()</h1>';
# 1. connect
try{
    $dbh = new PDO('mysql:host='.$mysql_host,$mysql_username,$mysql_password);
}catch(PDOException $e){
    stop($e->getMessage());
}
echo 'connected to mysql server<br>';

# 2. create database and table for tests
foreach(
    array(
        "CREATE SCHEMA IF NOT EXISTS `testdb`;",
        "CREATE TABLE IF NOT EXISTS `testdb`.`tbl`(
           `id` INT unsigned NOT NULL AUTO_INCREMENT PRIMARY KEY,
           `name` VARCHAR(16) NOT NULL
       );"
    ) as $query
){
    $stmt = $dbh->prepare($query);
    if(!$stmt->execute()){
        stop($stmt->errorInfo());
    }
}
echo 'created database and table if not already exists<br>';

# 3. multi insert via beginTransaction() and commit() / rollBack()
$dbh->beginTransaction();
echo '<b>$dbh->beginTransaction();</b><br>';
$sql = "
   INSERT INTO `testdb`.`tbl` SET `name` = 'a';
   INSERT INTO `testdb`.`tbl` SET `name` = 'b';
   INSERT INTO `testdb`.`tbl` SET `name` = 'c';
";
echo '<b>INSERT INTO `testdb`.`tbl` SET `name` = \'a\';</b><br><b>INSERT INTO `testdb`.`tbl` SET `name` = \'b\';</b><br><b>INSERT INTO `testdb`.`tbl` SET `name` = \'c\';</b><br>';
$stmt = $dbh->prepare($sql);
echo '<b>$stmt = $dbh->prepare($sql);</b><br>';
if(!$stmt->execute()){
    $dbh->rollBack();
    stop($stmt->errorInfo());
}else{
    ############################
    # INTERESTING PART IS HERE #
    ############################
    echo '<br><i>we will now ->commit()</i><br>';
    switch($type){
        case 'regular':
            echo '<h2>using regular way to see that the multi-inserts didnt work</h2>';
            $dbh->commit();
            echo 'fired <b>$dbh->commit();</b><br>';
            break;
        case 'alternative':
            echo '<h2>using the alternative way to see that they surprisingly worked</h2>';
            $stmt = null;
            echo '"destroyed" the $stmt: <b>$stmt = null;</b><br>';
            $dbh->commit();
            echo 'and now fired <b>$dbh->commit();</b><br>';
            break;
        default:
            stop('wrong type! use "regular" or "alternative"');
            break;
    }
}

# 4. now (have to) disconnect and reconnect to see if the INSERTS really worked:
# (you may try your self without reconnecting...)
$dbh = NULL;
try{
    $dbh = new PDO('mysql:host='.$mysql_host,$mysql_username,$mysql_password);
}catch(PDOException $e){
    stop($e->getMessage());
}
echo 'reconnected to mysql server<br>';

## 5. read tbl
echo 'read tbl: <b>SELECT * FROM `testdb`.`tbl`;</b><br>';
$stmt = $dbh->prepare("SELECT * FROM `testdb`.`tbl`;");
if(!$stmt->execute()){
    stop($stmt->errorInfo());
}else{
    while($row = $stmt->fetch(PDO::FETCH_ASSOC)){
        $res[] = $row;
    }
    echo '<b>result:</b><br>';
    if(!isset($res)){
        echo 'we got no data back from the mysql server<br>';
    }else{
        echo '<pre>';
        print_r($res);
        echo '</pre>';
    }
}

# e-handling
function stop($e){
    echo '<pre>';
    print_r($e);
    echo '</pre>';
    exit(0);
}

?>