Server OS: Solaris 9, Database server: IBM Informix IDS 9.4, Web Server Apache/2.0.54, PHP: 5.2.5, ODBC-driver: IBM Informix ODBC Driver
-------------------
Reproduce Code:

class MyBaseClass
{
	public $par1;
	private $par2;
	private $par3;
	public $par4;
}
class MyClass extends MyBaseClass 
{
	public $par5;
	public $par6;
	
	public function __construct($par1, $par4, $par5, $par6)
	{
		$this->par1 = $par1;
		$this->par2 = $par1;
		$this->par3 = $par4;
		$this->par4 = $par4;
		$this->par5 = $par5;
		$this->par6 = $par6;
	}	
}
		$db = new PDO("informix:connection string parameters", "user", "password");
		$stmt = $db->prepare("EXECUTE PROCEDURE mystoredprocedure()");
		$stmt->setFetchMode(PDO::FETCH_CLASS,'MyClass');
		$stmt->execute();
		$result = $stmt->fetchAll(PDO::FETCH_CLASS);
		print_r($result);
		
----------------------
Expected result:
Array ( [0] => MyClass Object (...
------------------------------
Actual result:
Array ( [0] => stdClass Object (...

Just use PDO::FETCH_CLASS, the flag PDO::FETCH_CLASSTYPE does it works differently.

As is mentioned in the source:
"fetch class gets its class name from 1st column".

Lets test it!

mysql> create table testz (name varchar(200));
Query OK, 0 rows affected (0.00 sec)

mysql> insert into testz values ('myclass');
Query OK, 1 row affected (0.00 sec)

mysql> insert into testz values ('myclass2');
Query OK, 1 row affected (0.00 sec)


class myclass { }
class myclass2 { }

$stmt->setFetchMode(PDO::FETCH_CLASS | PDO::FETCH_CLASSTYPE, 'myclass');
$stmt->execute();
$all = $stmt->fetchAll();

array(2) {
  [0]=>
  object(myclass)#3 (0) {
  }
  [1]=>
  object(myclass2)#4 (0) {
  }
}

Though currently the third parameter to setFetchMode is mandatory when using PDO::FETCH_CLASS, it seems incorret when using the flag FETCH_CLASSTYPE, as the class name come from a table column.

And yes, this must be documented.

Thanks. :)

Using the suggested approach from comment #14 would not solve the problem when passing along an array of constructor arguments unless the specified class has a constructor. Using stdClass for instance, results in PHP Fatal error:  Uncaught exception 'PDOException' with message 'SQLSTATE[HY000]: General error: user-supplied class does not have a constructor, use NULL for the ctor_params parameter, or simply omit it'. The number of arguments taken by the stand-in class' constructor doesn't have to be equal to the class returned by the first column of the query.

To use 'MyClass', just pass PDO::FETCH_CLASS. It's clearly written in documentation.