pg_lo_seek

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

pg_lo_seek — Seeks position within a large object

Descrierea

pg_lo_seek ( resource $large_object , int $offset [, int $whence = PGSQL_SEEK_CUR ] ) : bool

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.

Parametri

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) .

Valorile întoarse

Întoarce valoarea TRUE în cazul succesului sau FALSE în cazul eșecului.

Exemple

Example #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;
?>

Istoricul schimbărilor

Versiune Descriere
5.6.0 Added PostgreSQL 9.3's 64bit large object support. Both client and server must support PostgreSQL 9.3 and PHP must be 64bit build to use 64bit large object.

A se vedea și

  • pg_lo_tell() - Returns current seek position a of large object