PDO::pgsqlLOBCreate
Also remember that fread() will only parse the first 8192 bytes from the stream. Use..
<?php
$data = stream_get_contents($stream);
?>
.. if you have a larger output to parse.
PDO::pgsqlLOBOpen
(PHP 5 >= 5.1.2, PECL pdo_pgsql:1.0.1-1.0.2)
PDO::pgsqlLOBOpen — Opens an existing large object stream
Description
resource PDO::pgsqlLOBOpen
( string $oid
[, string $mode
] )
PDO::pgsqlLOBOpen() opens a stream to access the data referenced by oid . If mode is r, the stream is opened for reading, if mode is w, then the stream will be opened for writing. You can use all the usual filesystem functions, such as fread(), fwrite() and fgets() to manipulate the contents of the stream.
Note: This function, and all manipulations of the large object, must be called and carried out within a transaction.
Parameters
- oid
-
A large object identifier.
- mode
-
If mode is r, open the stream for reading. If mode is w, open the stream for writing.
Return Values
Returns a stream resource on success, or FALSE on failure.
Examples
Example #1 A PDO::pgsqlLOBOpen() example
Following on from the PDO::pgsqlLOBCreate() example, this code snippet retrieves the large object from the database and outputs it to the browser.
<?php
$db = new PDO('pgsql:dbname=test host=localhost', $user, $pass);
$db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
$db->beginTransaction();
$stmt = $db->prepare("select oid from BLOBS where ident = ?");
$stmt->execute(array($some_id));
$stmt->bindColumn('oid', $lob, PDO::PARAM_LOB);
$stmt->fetch(PDO::FETCH_BOUND);
fpassthru($lob);
?>
add a note
User Contributed NotesPDO::pgsqlLOBOpen
knl at bitflop dot com
26-Sep-2008 03:54
26-Sep-2008 03:54
knl at bitflop dot com
26-Sep-2008 01:20
26-Sep-2008 01:20
The above example is missing some data. After spending several hours trying to get it to work in vain, Jeff Davis from the PostgreSQL channel on IRC (freenode) figured out what was missing.
The below example will work, but you have to insert the MIME type and file size of the large object that you are storing, so you can use that data for extraction.
<?php
$db = new PDO('pgsql:dbname=test host=localhost', $user, $pass);
$db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
$db->beginTransaction();
$stmt = $db->prepare("SELECT oid, blob_type, filesize FROM BLOBS WHERE ident = ?");
$stmt->execute(array($some_id));
$stmt->bindColumn('oid', $lob, PDO::PARAM_LOB);
$stmt->bindColumn('blob_type', $blob_type, PDO::PARAM_STR);
$stmt->bindColumn('filesize', $filesize, PDO::PARAM_STR);
$stmt->fetch(PDO::FETCH_BOUND);
$stream = $pdo->pgsqlLOBOpen($lob, 'r');
$data = fread($stream, $filesize);
header("Content-type: $blob_type");
echo $data;
?>
Also fpassthru() will just give this result: Warning: fpassthru(): supplied argument is not a valid stream resource in ...
Use echo or print instead.