PDO::pgsqlLOBOpen
(PHP 5 >= 5.1.2, PHP 7, PECL pdo_pgsql >= 1.0.2)
PDO::pgsqlLOBOpen — Opens an existing large object stream
说明
$oid [,
string $mode = "rb" ] ) :
resource
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.
参数
-
oid -
A large object identifier.
-
mode -
If mode is r, open the stream for reading. If mode is w, open the stream for writing.
返回值
Returns a stream resource on success 或者在失败时返回 FALSE.
范例
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);
?>
参见
- PDO::pgsqlLOBCreate() - Creates a new large object
- PDO::pgsqlLOBUnlink() - Deletes the large object
- pg_lo_open() - 打开一个大型对象
