Edit report at http://bugs.php.net/bug.php?id=54169&edit=1

 ID:                 54169
 Comment by:         bugs dot php at pixbox dot co dot uk
 Reported by:        auroraeosr...@php.net
 Summary:            Garbage Pointers returned for (n)varchar(max)
                     columns (SQL Server)
 Status:             Assigned
 Type:               Bug
 Package:            PDO related
 Operating System:   Any
 PHP Version:        Irrelevant
 Assigned To:        auroraeosrose
 Block user comment: N
 Private report:     N

 New Comment:

I'm experiencing the same issue, using PHP 5, a Microsoft SQL Server
2008, and a 

direct ODBC connection.



My workaround was to alter the nvarchar(max) columns to nvarchar(n)
where n is 

whatever the suitable size for that column was, or text.



The really strange thing was that when it was returning gibberish, it
returned 

snippets of PHP code from the page that ran the query!


Previous Comments:
------------------------------------------------------------------------
[2011-03-05 17:06:22] auroraeosr...@php.net

Description:
------------
I found an issue this week that exists in both odbc and pdo_odbc with

SQL Server.  The ODBC implemention of Windows returns 0 as the length

for for varchar(max) and nvarchar(max).  This makes the allocation of

the strings incorrect and you get back garbage pointers for the

contents.



This was a pretty easy fix for pdo_odbc, simply check if the colsize

is returned as 0 and the type is one of the varchar types, if so

always treat it as a column with "long" data.  This works perfectly

without breaking things.  Attached is a patch that works for both 5.3

and trunk, includes an additional test for the issue.



ODBC shows the same issue - don't have a fix for that



Occurs in all versions of PHP



There are multiple bug reports concerning this and related to it - I'll
try to gather them all up (later)

Test script:
---------------
$db = new PDO('odbc:yourdsnhere', 'username', 'password');

$db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);

$db->exec('CREATE TABLE testing(id INT NOT NULL PRIMARY KEY, data
varchar(max))');

$insert = $db->prepare('INSERT INTO testing VALUES (?, ?)');

$insert->execute(array(1, str_repeat('i', 500)));

$stmt = $db->query('select * from testing');

var_dump($stmt->fetchAll());



unset($db, $insert, $smt);



// This shows the same issue in odbc

$db = odbc_connect ('yourdsnhere', 'username', 'password');

$stmt = odbc_exec($db, 'select * from testing');

var_dump(odbc_fetch_array($stmt));

Expected result:
----------------
array(1) { [0]=> array(4) { ["id"]=> string(1) "1" [0]=> string(1) "1"
["data"]=> string(500)
"iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii"
[1]=> string(500)
"iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii"
} }





Same for the odbc call

Actual result:
--------------
array(1) { [0]=> array(4) { ["id"]=> string(1) "1" [0]=> string(1) "1"
["data"]=> string(500)
"�-\p-\!������ˆòE�������ii����iiii!���!���select
* from
foo�iiiiii���!�������hall�iiiiiii!������ÀùE�������ii��������1���!���­|a���ìòEáE����ðE��������stmt����!���1���(áE����������������1���!�������������������`óEàõE$E
©"���1���1�����������óE����àõE������������€������1���1�������������������óE�������@éEøëE���!���1���àóEô������������������!���iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii"
[1]=> string(500)
"�-\p-\!������ˆòE�������ii����iiii!���!���select
* from
foo�iiiiii���!�������hall�iiiiiii!������ÀùE�������ii��������1���!���­|a���ìòEáE����ðE��������stmt����!���1���(áE����������������1���!�������������������`óEàõE$E
©"���1���1�����������óE����àõE������������€������1���1�������������������óE�������@éEøëE���!���1���àóEô������������������!���iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii"
} } array(2) { ["id"]=> string(1) "1" ["data"]=> string(500)
"�èE8öEp�����HöEHöE$.\päE����icrosoft][SQL
Server Native Client 10.0]String data, right
truncation��������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������������ï¿
 
½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½ï¿½"
} 


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