php - mysql_num_rows();和标题()；给出重定向循环

Question

我在使用 header() 时遇到重定向循环错误；在 mysql_num_rows() 之后；如果我替换 header(); with echo 没有重定向循环错误。

<?php

  require("includes/inc.php");

$id = trim(sanitize($_GET['id'])); //Receives the id of the file from the url

$fileid = mysql_query("SELECT * FROM files WHERE fileid = '$id'");
    if (mysql_num_rows($fileid) != 1) {
        header('Location: download.php?error=invalid_file');
    } else {
        echo "File Exist";
    }

?>

Answer 1

试试这个。如果不起作用请告诉我

<?php

  require("includes/inc.php");

$id = trim(sanitize($_GET['id'])); //Receives the id of the file from the url

if($id)
{
    $fileid = mysql_query("SELECT * FROM files WHERE fileid = '$id'");
    if (mysql_num_rows($fileid) != 1) {
        header('Location: download.php?error=invalid_file');
    } else {
        echo "File Exist";
    }
}
?>