NCLOB support in OCI8

Question

I'm currently developing a multilingual website with PHP and Oracle and I'm facing a problem concerning NCLOBs. I know that the "The Underground PHP and Oracle Manual" states that all NCHAR-related data types are not supported. However, apparently NCHAR and NVARCHAR2 do work just fine. So I'm wondering how up to date this information is. Anyway, the problem is that I can't write to NCLOB columns via OCI-Lob::write. The call succeeds and returns the number of chars written, but the column stays empty. Is there any hope I can get this to work? If not, is there another library that I could use to connect PHP with the database that supports NCLOBs?
I'm using the following code:
$s = oci_parse($dbc, "INSERT INTO trouble (xnclob) values (EMPTY_CLOB()) returning xnclob into :lob");
$lob = oci_new_descriptor($dbc);
oci_bind_by_name($s, "lob", $lob, -1, SQLT_CLOB);
$result = oci_execute($s, OCI_NO_AUTO_COMMIT);
$lob->write($data); // Succeeds, but column stays empty!
oci_commit($dbc);
The code seems to work fine with BLOBs and normal CLOBs. Out test server is running the following software:
CentOS 6.4 64-Bit
PHP 5.3.3
OCI8 1.4.9
Oracle 11g Release 2 XE
Thanks for the help in advance.
Best regards
David

Answer 1

The choices are (1) use UTF8 as the base character set and don't use
NCHAR/NVARCHAR/NCLOB or (2) submit patches to PHP OCI8 to add NCLOB
support or (3) use another language.
I wouldn't trust NCHAR/NVARCHAR to work consistently in PHP OCI8,
despite (or because of) there being automatic mapping to non N* types
in some cases.
I know you might be using XE 11.2 just for testing. However, if you
are targeting that edition for production use, the character set is
AL32UTF8 so there isn't a direct need to use NCHAR/NVARCHAR/NCLOB.
From Choosing a Character Set:
"Oracle recommends using SQL CHAR, VARCHAR2, and CLOB data types in [a] AL32UTF8
database to store Unicode character data. Use of SQL NCHAR,NVARCHAR2, and NCLOB
should be considered only if you must use a database whose database character set
is not AL32UTF8."
Regarding CentOS, I would recommend using Oracle Linux which is free
to download & install, has free patches etc, has a faster kernel than
RHEL available, and is the OS we test the DB on.  You can get it from
http://public-yum.oracle.com/
If possible target a newer version of PHP.  PHP 5.3 is in security
fix-only mode, and this will end soon.  I would recommend building
your own PHP, or using Zend Server (either the free or paid edition).
For new development, use PHP 5.5.