php教程

pg_lo_read_all

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

pg_lo_read_all 读入整个大型对象并直接发送给浏览器

说明

pg_lo_read_all ( resource $large_object ) : int

pg_lo_read_all() 读入一个大型对象并在(PHP)发送完所有待发的 header 之后将其直接发送给浏览器。主要目的是发送图片或声音等二进制数据。返回值为读入的字节数,如果出错则返回 FALSE

要使用大型对象(lo)接口,需要将其放置在事务块中。

Note:

本函数以前的名字为 pg_loreadall()

参见 pg_lo_read()

User Contributed Notes

fabar2 at libero dot it 08-Oct-2011 08:36
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.
robert dot bernier5 at sympatico dot ca 24-Sep-2004 07:45
// 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");

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