(PHP 4 >= 4.2.0, PHP 5, PHP 7)
pg_lo_export — 将大型对象导出到文件
$connection
], int $oid
, string $pathname
)pg_lo_export() takes a large object in a PostgreSQL database and saves its contents to a file on the local filesystem.
要使用大型对象（lo）接口，需要将其放置在事务块中。
Note:
本函数以前的名字为 pg_loexport()。
connection
PostgreSQL database connection resource. When
connection is not present, the default connection
is used. The default connection is the last connection made by
pg_connect() or pg_pconnect().
oid要导出的数据库里的大型对象的 OID。
pathname要导出的数据库里的大型对象的文件在客户端上完整路径和文件名。
成功时返回 TRUE， 或者在失败时返回 FALSE。
Example #1 pg_lo_export() example
<?php
$database = pg_connect("dbname=jacarta");
pg_query($database, "begin");
$oid = pg_lo_create($database);
$handle = pg_lo_open($database, $oid, "w");
pg_lo_write($handle, "large object data");
pg_lo_close($handle);
pg_lo_export($database, $oid, '/tmp/lob.dat');
pg_query($database, "commit");
?>