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pg_lo_read_all

(PHP 4 >= 4.2.0, PHP 5, PHP 7, PHP 8)

pg_lo_read_all — 读取整个大对象并直接发送到浏览器

说明

pg_lo_read_all(PgSql\Lob $lob): int

pg_lo_read_all() 读取大对象并在发送完所有待发的 header 之后将其直接发送给浏览器。主要用于发送图片或声音等二进制数据。

要使用大对象接口，必须将其封装在一个事务块中。

注意:
本函数以前的名字为 pg_loreadall()。

参数

lob: 通过 pg_lo_open() 返回的 PgSql\Lob 实例。

返回值

读取的字节数。

更新日志

版本	说明
8.1.0	现在 `lob` 接受 PgSql\Lob 实例，之前接受 resource。

示例

示例 #1 pg_lo_read_all() 示例

<?php
   header('Content-type: image/jpeg');
   $image_oid = 189762345;
   $database = pg_connect("dbname=jacarta");
   pg_query($database, "begin");
   $handle = pg_lo_open($database, $image_oid, "r");
   pg_lo_read_all($handle);
   pg_query($database, "commit");
?>

参见

pg_lo_read() - 读取大对象

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User Contributed Notes 2 notes

down

robert dot bernier5 at sympatico dot ca ¶

19 years ago

// remember, large objects must be obtained from within a transaction
pg_query ($dbconn, "begin");

// "assume" for this example that the large object resource number of the zipped file is "17899"

$lo_oid = 17899;

$handle_lo = pg_lo_open($dbconn,$lo_oid,"r") or die("<h1>Error.. can't get handle</h1>");

//headers to send to the browser before beginning the binary download
header('Accept-Ranges: bytes');
header('Content-Length: 32029974'); //this is the size of the zipped file
header('Keep-Alive: timeout=15, max=100');
header('Content-type: Application/x-zip');
header('Content-Disposition: attachment; filename="superjob.zip"');

pg_lo_read_all($handle_lo) or 
  die("<h1>Error, can't read large object.</h1>");

// committing the data transaction
pg_query ($dbconn, "commit");

down

fabar2 at libero dot it ¶

12 years ago

Pay attention that if you omit the "length" parameter it will read a 8192 bytes object regardless to its real dimensions. If you want to use this function think to save the object size somewhere (usually a field in its table) before reading the object. Alternatively use the pg_lo_readall function.

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