Edit report at https://bugs.php.net/bug.php?id=60994&edit=1
ID: 60994
Comment by: ashnazg@php.net
Reported by: php dot net at boedah dot de
Summary: PDO_OCI: Reading a multibyte CLOB caps at 8192
characters
Status: Open
Type: Bug
Package: PDO OCI
Operating System: OEL 5 / RHEL5 / Win7
PHP Version: Irrelevant
Block user comment: N
Private report: N
New Comment:
Comments on my experience with this bug -- http://stackoverflow.com/questions/33026617/pdo-oci-truncates-large-multibyte-clobs
I had the same experience using raw OCI, but found a way to work around it by passing a length value
to LOB->read() that is larger than the actual CLOB, thus forcing it to read it all in one big
read rather than in smaller chunks via a "while !LOB->eof() then LOB->read()" loop.
Since PDO OCI already transforms the LOB into a Stream internally before returning it in my row, I
have to guess that it is internally doing the same kind of loop, and thus is losing data in the same
way.
Since I can't see a way in PDO OCI to force the same read-it-all-at-once behavior, I'm
stuck.
My environments:
- PHP 5.5.24 on RHEL6, oci8 v1.4.10
- PHP 5.5.11 on Win7, oci8 v1.4.10
Previous Comments:
------------------------------------------------------------------------
[2012-02-06 16:20:20] php dot net at boedah dot de
adding the full code sample as patch did not work in the first place
-> attached it now
------------------------------------------------------------------------
[2012-02-06 16:13:52] php dot net at boedah dot de
Description:
------------
Inserting large multibyte strings works fine,
reading them back in results in only 8192 characters read (=24576 bytes).
Even if inserting mixed single-multibyte strings, reading caps at 8192
characters (even though the byte count is far less).
Inserting and reading 100000 single bytes work, though.
Attached a file with more debug output.
== PHP ==
We are using ZendServer 5.5.0:
PHP 5.3.8-ZS5.5.0 (cli) (built: Aug 23 2011 05:20:27)
Copyright (c) 1997-2011 The PHP Group
Zend Engine v2.3.0, Copyright (c) 1998-2011 Zend Technologies
But this bug also is on PHP 5.4.0RC8-dev
== Oracle ==
Oracle XE 10.2.0.1, but also on Enterprise 10.2.0.4.0.
Characterset: AL32UTF8
Test table:
create table TEST_LOB (
tl_id NUMBER(3),
tl_byte_16 VARCHAR2(16 BYTE),
tl_char_16 VARCHAR2(16 CHAR),
tl_byte_4000 VARCHAR2(4000 BYTE),
tl_char_4000 VARCHAR2(4000 CHAR),
tl_blob BLOB,
tl_clob CLOB,
tl_date DATE,
tl_number NUMBER
)
Test script:
---------------
$dsn = 'oci:dbname=(DESCRIPTION=(ADDRESS_LIST=(
ADDRESS=(PROTOCOL=TCP)(HOST=localhost)(PORT=1521)))
(CONNECT_DATA=(SID=xe)));charset=AL32UTF8';
$username = 'USER';
$password = 'PW';
$lobTestTablename = 'TEST_LOB';
$id = -1;
$clobData = str_repeat('â¦', 8193);
$pdo = new PDO($dsn, $username, $password);
$pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
$pdo->exec("delete from $lobTestTablename where tl_id < 0");
$pdoStmt = $pdo->prepare("insert into $lobTestTablename (tl_id, tl_clob) values (?,
?)");
$pdoStmt->bindParam(1, $id, PDO::PARAM_INT, null, null);
$pdoStmt->bindParam(2, $clobData, PDO::PARAM_STR, strlen($clobData), null);
$pdoStmt->execute();
$pdoStmt = $pdo->query("select * from $lobTestTablename where TL_ID = $id");
$row = $pdoStmt->fetch(PDO::FETCH_ASSOC);
$dataRead = stream_get_contents($row['TL_CLOB']);
printf("values equal: %s\n", var_export($clobData === $dataRead, true));
Expected result:
----------------
values equal: false
Actual result:
--------------
values equal: true
------------------------------------------------------------------------
--
Edit this bug report at https://bugs.php.net/bug.php?id=60994&edit=1