如何从PDO中的存储函数中获取返回值？

I have this code :

我有这个代码:

include("connect.php");
// Call database function
$p = 100;
$sth = $conn->prepare('SELECT ISPPRO.USERPKG.GET_USER(:bind1, :bind3) AS v FROM DUAL');
$sth->bindParam(":bind1", $p, PDO::PARAM_INT);
$sth->bindParam(":bind3", $p, PDO::PARAM_INT);
$sth->execute();
$result = $sth->fetch(PDO::FETCH_ASSOC);
print_r( $result);
echo "<br><pre>";
print_r($conn->errorInfo());
echo "</pre>";
include("connect