From: uwendel at mysql dot com Operating system: PHP version: 5.3CVS-2008-03-11 (CVS) PHP Bug Type: PDO related Bug description: PDO::FETCH_SERIALIZE calls __construct()
Description: ------------ There seems to be very few documentation about PDO::FETCH_SERIALIZE in the PHP manual but playing the guessing game from the code it seems that this feature aims to support SPL/Serialize interface. As I'm not sure about the purpose of PDO::FETCH_SERIALIZE I'm not sure if the following is a bug or not. However, it seems to me that PDO::FETCH_SERIALIZE unintentionally calls __construct(). One of the main ideas behind SPL/Serialize interface seems to be that for unserialization the constructor of a class does not get called. The constructor of a class has a different meaning than a helper function like unserialize() and thus should not be called automatically. Let's check: class myclass implements Serialize { public function __construct() { printf("%s()\n", __METHOD__); } public function serialize() { printf("%s()\n", __METHOD__); return "any data from serialize()"; } public function unserialize($dat) { printf("%s(%s)\n", __METHOD__, var_export($dat, true)); } } $obj1 = new myclass() ---> myclass::__construct() $tmp = serialize($obj1) $obj2 = unserialize($tmp) ---> myclass::unserialize('any data from serizalize()') __construct() gets called only once for object creation but not again during unserialization. Let's try that with PDO: [...] $stmt = $db->query("SELECT dat FROM test"); $rows = $stmt->fetchAll(PDO::FETCH_CLASS|PDO::FETCH_SERIZALIZE, "myclass"); --> myclass::unserialize("data from DB") --> myclass::__construct() [...] PDO first calls unserialize() as its supposed to do. But then it also calls __construct() which is against the idea of the Serialize interface not to call the constructor automatically during unserialization. Reproduce code: --------------- sapi/cli/php -r '$db = new PDO("sqlite:/tmp/foo"); $db->exec("DROP TABLE test"); $db->exec("CREATE TABLE test(dat VARCHAR(100))"); $db->exec("INSERT INTO test(dat) VALUES (\"Data from DB\")"); class myclass implements Serializable { public function __construct() { printf("%s()\n", __METHOD__); } public function serialize() { return "any data from serizalize()"; } public function unserialize($dat) { printf("%s(%s)\n", __METHOD__, var_export($dat, true)); }} $stmt = $db->query("SELECT * FROM test"); var_dump($stmt->fetchAll(PDO::FETCH_CLASS|PDO::FETCH_SERIALIZE, "myclass")); $obj = new myclass(); var_dump(unserialize(serialize($obj)));' myclass::unserialize('Data from DB') myclass::__construct() array(1) { [0]=> object(myclass)#3 (0) { } } myclass::__construct() myclass::unserialize('any data from serizalize()') object(myclass)#4 (0) { } -- Edit bug report at http://bugs.php.net/?id=44409&edit=1 -- Try a CVS snapshot (PHP 5.2): http://bugs.php.net/fix.php?id=44409&r=trysnapshot52 Try a CVS snapshot (PHP 5.3): http://bugs.php.net/fix.php?id=44409&r=trysnapshot53 Try a CVS snapshot (PHP 6.0): http://bugs.php.net/fix.php?id=44409&r=trysnapshot60 Fixed in CVS: http://bugs.php.net/fix.php?id=44409&r=fixedcvs Fixed in release: http://bugs.php.net/fix.php?id=44409&r=alreadyfixed Need backtrace: http://bugs.php.net/fix.php?id=44409&r=needtrace Need Reproduce Script: http://bugs.php.net/fix.php?id=44409&r=needscript Try newer version: http://bugs.php.net/fix.php?id=44409&r=oldversion Not developer issue: http://bugs.php.net/fix.php?id=44409&r=support Expected behavior: http://bugs.php.net/fix.php?id=44409&r=notwrong Not enough info: http://bugs.php.net/fix.php?id=44409&r=notenoughinfo Submitted twice: http://bugs.php.net/fix.php?id=44409&r=submittedtwice register_globals: http://bugs.php.net/fix.php?id=44409&r=globals PHP 4 support discontinued: http://bugs.php.net/fix.php?id=44409&r=php4 Daylight Savings: http://bugs.php.net/fix.php?id=44409&r=dst IIS Stability: http://bugs.php.net/fix.php?id=44409&r=isapi Install GNU Sed: http://bugs.php.net/fix.php?id=44409&r=gnused Floating point limitations: http://bugs.php.net/fix.php?id=44409&r=float No Zend Extensions: http://bugs.php.net/fix.php?id=44409&r=nozend MySQL Configuration Error: http://bugs.php.net/fix.php?id=44409&r=mysqlcfg