Bug #41388 [Opn->Nab]: Error in COM Object results
Edit report at https://bugs.php.net/bug.php?id=41388&edit=1
ID: 41388
Updated by: cmb@php.net
Reported by: superfelo at yahoo dot com
Summary: Error in COM Object results
-Status: Open
+Status: Not a bug
Type: Bug
Package: COM related
Operating System: Windows XP and 2003
PHP Version: 5.2.2
-Assigned To:
+Assigned To: cmb
Block user comment: N
Private report: N
New Comment:
According to the docs[1], getChunk() returns a Variant. The
subtype isn't specified, but it is likely VT_ARRAY|VT_UI1 (you can
verify that with variant_get_type ()). If you echo this Variant
(or otherwise convert it to a PHP string), internally it is
converted to an BSTR which is converted to a PHP string according
to the code page, which can't possibly work as intended. Instead
you have to convert the Variant to a PHP array manually; for
instance:
$bytes = [];
foreach ($rst->Fields["Campo1"]->GetChunk(1,20) as $byte) {
$bytes[] = chr($byte);
}
echo implode('', $bytes);
[1] <https://docs.microsoft.com/en-us/office/client-developer/access/desktop-database-reference/field-getchunk-method-dao>
Previous Comments:
------------------------------------------------------------------------
[2008-11-18 16:33:48] xxx at xxx dot cc
?Se arreglar? alguna vez?
?Hay alguien trabajando en el problema?
Will fix any time?
Is anyone working on the problem?
------------------------------------------------------------------------
[2007-12-19 13:26:19] superfelo at yahoo dot com
Is there any progress?
Is working on the problem?
------------------------------------------------------------------------
[2007-08-15 08:33:02] jani@php.net
Assigned to the maintainer.
------------------------------------------------------------------------
[2007-05-14 15:29:36] superfelo at yahoo dot com
Description:
------------
As it is possible to see bellow, a COM Object is opened, then Data Base is read by a Recordset and a
OLE object is loaded in such Recordset.
Later, using a GetChunk which is a Recordset function a number of bytes in OLE object is read but
this function just result in the number of printable characters and it discards or ignore for
instance, byte 0 or any other not printable character.
In the second example, it is possible to see a function to read 20 bytes after a certain position.
Now the problem is similar. The 20 bytes has been counted by the results are just printable
characters of such 20 bytes. So, result is less than 20 character because not all 20 characters are
printable.
Reproduce code:
---------------
$engine = new COM("DAO.DBEngine.35");
$engine->SystemDB = "c:\system.mda";
$engine->defaultuser = "admin";
$engine->defaultpassword = "";
$db = $engine->OpenDataBase("c:\bd.mdb");
$sqlstr = "SELECT DISTINCTROW tabla1.* FROM tabla1;" ;
$rst = $db->OpenRecordset("RsConfig",$sqlstr);
echo $rst->Fields["Campo1"]->GetChunk(1,20);
//-------------------------------------------------
$mstream = new COM("ADODB.Stream");
$mstream->Type = 1; // 'adTypeBinary
$mstream->Open;
$mstream->Write($rst->Fields["Campo1"]->Value);
$mstream->position = 0;
echo $mstream->Read(20);
Expected result:
----------------
The actual number of bytes in a OLE object stored in a Recordset: This number of bytes of course,
must include printable and not printable characters.
Actual result:
--------------
Just the number of printable characters.
------------------------------------------------------------------------
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Edit this bug report at https://bugs.php.net/bug.php?id=41388&edit=1
Thread (6 messages)