Be aware when you modify a lo with pg_lowrite() to remove first the old one : if the new lo is smaller than the one before, it only overwrite the begining and you keep the end of the old lo (open with "w" parameter, PHP 4.04 Linux RH).
(PHP 4 >= 4.2.0, PHP 5, PHP 7, PHP 8)
pg_lo_write — Escreve em um objeto grande
pg_lo_write() grava dados em um objeto grande na posição de busca atual.
Para usar a interface de objeto grande, é necessário incluí-la em um bloco de transação.
Nota:
Esta função costumava ser chamada de pg_lowrite().
lobUma instância de PgSql\Lob, retornada por pg_lo_open().
data
Os dados a serem gravados no objeto grande. Se length for
um int e for menor que o comprimento de data, apenas
os bytes de length serão gravados.
length
Um número máximo opcional de bytes a serem gravados. Deve ser maior que zero
e não maior que o comprimento dos data. O padrão é
o comprimento dos data.
O número de bytes gravados no objeto grande, ou false em caso de erro.
| Versão | Descrição |
|---|---|
| 8.1.0 |
O parâmetro lob agora espera uma instância de PgSql\Lob;
anteriormente, um resource era esperado.
|
| 8.0.0 |
length agora é anulável.
|
Exemplo #1 Exemplo de pg_lo_write()
<?php
$doc_oid = 189762345;
$data = "This will overwrite the start of the large object.";
$database = pg_connect("dbname=jacarta");
pg_query($database, "begin");
$handle = pg_lo_open($database, $doc_oid, "w");
$data = pg_lo_write($handle, $data);
pg_query($database, "commit");
?>Be aware when you modify a lo with pg_lowrite() to remove first the old one : if the new lo is smaller than the one before, it only overwrite the begining and you keep the end of the old lo (open with "w" parameter, PHP 4.04 Linux RH).Using php 4.3.0 and PostgreSQL 7.3.1
I can write a simple script in which pg_lo_write seems to always return 1 and not the number of bytes written, as evidenced by extracting the data through another means.
Further more, I can make this pg_lo_write fail, or at least fail to write all the data it's pretty difficult to tell without the number of bytes written being returned, and not return the false value. In addition to this, the lo resource has been adjusted so that the oid it contains is 0.
Unfortunately, I do not know what exactly the failure mode is, it does seem to be in the ip network communication side of PostgreSQL, which is odd since the unix domain comms works fine for this. However, it would have been useful to have the pg_lo_write() function return as advertised, it would have saved some of the 2 man hours me and the dev. team put into diagnosing this problem.