(PHP 5 >= 5.1.2, PECL pdo_pgsql >= 1.0.2)
PDO::pgsqlLOBOpen — Opens an existing large object stream
$oid
[, string $mode = "rb"
] )
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.
oid
A large object identifier.
mode
If mode is r, open the stream for reading. If mode is w, open the stream for writing.
Returns a stream resource on success 或者在失败时返回 FALSE.
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', $oid, PDO::PARAM_STR);
$stmt->fetch(PDO::FETCH_BOUND);
$stream = $db->pgsqlLOBOpen($oid, 'r');
header("Content-type: application/octet-stream");
fpassthru($stream);
?>