pg_lo_open

说明

resource pg_lo_open ( resource connection, int oid, string mode )

pg_lo_open() 打开一个大型对象并返回大型对象资源号。该资源号内封装了连接号。oid 指定了有效的大型对象的 oid，mode 可以为 "r"，"w" 或者 "rw"。如果失败则返回 FALSE。

警告

在关闭大型对象资源之前不要关闭数据库连接。

要使用大型对象（lo）接口，需要将其放置在事务块中。

注: 本函数以前的名字为 pg_loopen()。

参见 pg_lo_close() 和 pg_lo_create()。

add a note User Contributed Notes

metator at netcabo dot pt
30-Aug-2005 02:15


Just for the record, a user must be a superuser (database owner) in order to invoke pg_lo_open() (though pg_lo_create() may be invoked...). This opens a gigantic security hole in the db. If a user is not a superuser, db will raise an error with message "Can't create Large Object.". 

Thus, imho, one should use pg_escape_bytea() instead.

riccardo_ridenti at hotmail dot com
24-Oct-2002 06:49


//INSERT FILE INTO DB

$fp = fopen($filename,"r");

        $buffer = fread($fp,filesize($filename));

    fclose($fp);

    pg_query ($conn, "begin");

    $oid = pg_lo_create ($conn);

    //echo "$oid\n";

      $rs = pg_exec($conn,"insert into table(object) values($oid);");//object field type must be "oid"

    $handle = pg_lo_open ($conn, $oid, "w");

    //echo "$handle\n";

    pg_lo_write ($handle, $buffer);

    pg_lo_close ($handle);

    pg_query ($conn, "commit"); //OR END

pg_close();



//GET BUFFER(file) FROM DB

$rs = pg_exec($conn,"select object from objects where id = xxxxxx;");

$row = pg_fetch_row($rs,0);

pg_query ($conn, "begin");

    $loid = pg_lo_open($conn,$row[0], "r");

    pg_lo_read_all ($loid);

    pg_lo_close ($loid);

pg_query ($conn, "commit"); //OR END

pg_close();

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