通过PHP查询Oracle中的存储过程 - 不工作

I simply don't get it.

I can connect fine to the Oracle database, but my account can only execute stored procedures. So I try to use one.

echo "before";

$nrows = '';
$stid = oci_parse($conn, 'begin :r := AR_INTEGRATIONS.F_SRVCIMPROVE_ACCNT_INCS(:p); end');
oci_bind_by_name($stid, ':p', '');
oci_bind_by_name($stid, ':r', $nrows);

if(!oci_execute($stid)){
 $e = oci_error();
 print htmlentities($e['message']);
 exit;
}



echo "<br/>After";

When I load this on my browser, it's blank. But when I comment out the oci_bind_by_name() lines, it displays before but not after.

This is the first time I'm using PHP to connect to Oracle and execute queries. It's very different from just using MySQL.

What's going on?