PHP Conference Nagoya 2025

pg_lo_create

(PHP 4 >= 4.2.0, PHP 5, PHP 7, PHP 8)

pg_lo_createCreate a large object

Description

pg_lo_create(PgSql\Connection $connection = ?, mixed $object_id = ?): int
pg_lo_create(mixed $object_id): int

pg_lo_create() creates a large object and returns the OID of the large object. PostgreSQL access modes INV_READ, INV_WRITE, and INV_ARCHIVE are not supported, the object is created always with both read and write access. INV_ARCHIVE has been removed from PostgreSQL itself (version 6.3 and above).

To use the large object interface, it is necessary to enclose it within a transaction block.

Instead of using the large object interface (which has no access controls and is cumbersome to use), try PostgreSQL's bytea column type and pg_escape_bytea().

Note:

This function used to be called pg_locreate().

Parameters

connection

An PgSql\Connection instance. When connection is unspecified, the default connection is used. The default connection is the last connection made by pg_connect() or pg_pconnect().

Warning

As of PHP 8.1.0, using the default connection is deprecated.

object_id

If an object_id is given the function will try to create a large object with this id, else a free object id is assigned by the server. The parameter relies on functionality that first appeared in PostgreSQL 8.1.

Return Values

A large object OID, or false on failure.

Changelog

Version Description
8.1.0 The connection parameter expects an PgSql\Connection instance now; previously, a resource was expected.

Examples

Example #1 pg_lo_create() example

<?php
$database
= pg_connect("dbname=jacarta");
pg_query($database, "begin");
$oid = pg_lo_create($database);
echo
"$oid\n";
$handle = pg_lo_open($database, $oid, "w");
echo
"$handle\n";
pg_lo_write($handle, "large object data");
pg_lo_close($handle);
pg_query($database, "commit");
?>

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andrea dot galli at acotel dot com
21 years ago
<?php
// --------- OPEN CONN ---

$conn = pg_connect("host='127.0.0.1' dbname='test' user='usertest' password='passtest'");

// --------- OPEN FILE ---

$fp = fopen('logo.gif', "r");
$buffer = fread($fp, filesize('logo.gif'));
fclose($fp);

// --------- CREATE - INSERT OID ---

pg_exec($conn, "begin");

$oid = pg_locreate($conn);

$rs = pg_exec($conn,"INSERT INTO test(tipo, images) VALUES('A1', $oid);");
$handle = pg_loopen ($conn, $oid, "w");

pg_lowrite ($handle, $buffer);
pg_loclose ($handle);

pg_exec($conn, "commit");

// --------- OPEN - INSERT OID ---

$rs = pg_exec($conn, "SELECT images FROM test WHERE tipo = 'A1';");
$row = pg_fetch_row($rs, 0);

pg_exec($conn, "begin");
$loid = pg_loopen($conn, $row[0], "r");

header("Content-type: image/gif");

pg_loreadall($loid);
pg_loclose($loid);

pg_exec ($conn, "commit");

// --------- UNLINK OID ---

pg_exec($conn, "begin");

$loid = $row[0];
pg_lounlink($conn, $loid);

pg_exec ($conn, "commit");

// --------- DELETE OID ---

pg_exec($conn, "DELETE FROM test WHERE tipo = 'A1';");

// --------- CLOSE CONN ---

pg_close();
?>
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