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pg_lo_seek

pg_lo_seek

(PHP 4 >= 4.2.0, PHP 5)

pg_lo_seek --  Seeks position within a large object

Popis

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.

Seznam parametrů

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) .

Návratové hodnoty

Vrací TRUE při úspěchu, FALSE při selhání.

Příklady

Příklad 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;
?>

Viz také

pg_lo_tell()