pg_lo_seek
(PHP 4 >= 4.2.0, PHP 5)
pg_lo_seek --
Seeks position within a large object
Описание
bool
pg_lo_seek ( resource large_object, int offset [, int whence] )
pg_lo_seek() seeks a position within a large object
resource.
To use the large object interface, it is necessary to
enclose it within a transaction block.
Список параметров
- large_object
PostgreSQL large object (LOB) resource, returned by pg_lo_open().
- offset
The number of bytes to seek.
- whence
One of the constants PGSQL_SEEK_SET (seek from object start),
PGSQL_SEEK_CUR (seek from current position)
or PGSQL_SEEK_END (seek from object end) .
Возвращаемые значения
Возвращает TRUE в случае успешного завершения или FALSE в случае возникновения ошибки.
Примеры
Пример 1. pg_lo_seek() example
<?php
$doc_oid = 189762345;
$database = pg_connect("dbname=jacarta");
pg_query($database, "begin");
$handle = pg_lo_open($database, $doc_oid, "r");
// Skip first 50000 bytes
pg_lo_seek($handle, 50000, PGSQL_SEEK_SET);
// Read the next 10000 bytes
$data = pg_lo_read($handle, 10000);
pg_query($database, "commit");
echo $data;
?>
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