未定义的索引：php中的id [英] Undefined index: id in php
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问题描述
我在PHP代码中遇到问题。我从电子书中获得了一些代码，但是当我尝试运行系统时，它会给出一些错误。我通过给出正确的引号修正了一些错误，但现在我遇到了其他一些错误。
I'm having a problem in PHP code. I got some code from an e-book, but when I tried to run the system, it's giving some errors. I fixed some of the errors by giving proper quotation marks, but now I'm stuck with some other errors.
如果有人帮助我，我会非常高兴出现以下错误：
I'd be more than happy if some one helps me with the following error:
注意：第4行的C：\ xampp \ htdocs \ autction \ index.php中的未定义索引：id
这是我的index.php代码：
This is my code for index.php:
<?php
require("config.php");
require("functions.php");
$validid = pf_validate_number($_GET['id'], "value", $config_basedir);
require("header.php");
if($validid == 0) {
$sql = "SELECT items.* FROM items WHERE dateends > NOW()";
}
else {
$sql = "SELECT * FROM items WHERE dateends > NOW()
AND cat_id = " . $validid . ";";
}
$result = mysql_query($sql);
$numrows = mysql_num_rows($result);
echo "<h1>Items available</h1>";
echo "<table cellpadding='5'>";
echo "<tr>";
echo "<th>Image</th>";
echo "<th>Item</th>";
echo "<th>Bids</th>";
echo "<th>Price</th>";
echo "</tr>";
if($numrows == 0) {
echo "<tr><td colspan=4>No items!</td></tr>";
}
else {
while($row = mysql_fetch_assoc($result)) {
$imagesql = "SELECT * FROM images WHERE
item_id = " . $row['id'] . " LIMIT 1";
$imageresult = mysql_query($imagesql);
$imagenumrows = mysql_num_rows($imageresult);
echo "<tr>";
if($imagenumrows == 0) {
echo "<td>No image</td>";
}
else {
$imagerow = mysql_fetch_assoc($imageresult);
echo "<td><img src='./images/". $imagerow['name'] . "' width='100'></td>";
}
echo "<td>";
echo "<a href='itemdetails.php?id="
. $row['id'] . "'>" . $row['name'] . "</a>";
if($_SESSION['USERID'] == $row['user_id']) {
echo " - [<a href='edititem.php?id="
. $row['id'] . "'>edit</a>]";
}
echo "</td>";
$bidsql = "SELECT item_id, MAX(amount) AS
highestbid, COUNT(id) AS numberofbids FROM bids
WHERE item_id=" . $row['id'] . " GROUP BY item_id;";
$bidresult = mysql_query($bidsql);
$bidrow = mysql_fetch_assoc($bidresult);
$bidnumrows = mysql_num_rows($bidresult);
echo "<td>";
if($bidnumrows == 0) {
echo "0";
}
else {
echo $bidrow['numberofbids'] . "</td>";
}
echo "<td>" . $config_currency;
if($bidnumrows == 0) {
echo sprintf('%.2f', $row['startingprice']);
}
else {
echo sprintf('%.2f', $bidrow['highestbid']);
}
echo "</td>";
echo "<td>" . date("D jS F Y g.iA",
strtotime($row['dateends'])) . "</td>";
echo "</tr>";
}
}
echo "</table>";
require("footer.php");
?>
有些人问，id来自哪里。我不知道，但我在其他文件中搜索过，这里是：
Some of you asked, where the id is coming from. I have no idea, but I searched it in other files, and here are they:
bar.php：
<?php
require("header.php");
$catsql = "SELECT * FROM categories ORDER BY category ASC;";
$catresult = mysql_query($catsql);
echo "<h1>Categories</h1>";
echo "<ul>";
echo "<li><a href='index.php'>View All</a></li>";
while($catrow = mysql_fetch_assoc($catresult)) {
echo "<li><a href='index.php?id=". $catrow['id'] . "'>" . $catrow['category']. "</a> </li>";
}
echo "</ul>";
?>
header.php：
header.php:
<?php
session_start();
require("config.php");
$db = mysql_connect($dbhost, $dbuser, $dbpassword);
mysql_select_db($dbdatabase, $db);
?>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01
Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<title><?php echo $config_forumsname; ?></title>
<link rel="stylesheet" href="stylesheet.css" type="text/css" />
</head>
<body>
<div id="header">
<h1>BidTastic Auctions</h1>
<div id="menu">
<a href="index.php">Home</a>
<?php
if(isset($_SESSION['USERNAME']) == TRUE) {
echo "<a href='logout.php'>Logout</a>";
}
else {
echo "<a href='login.php'>Login</a>";
}
?>
<a href="newitem.php">New Item</a>
</div>
<div id="container">
<div id="bar">
<?php require("bar.php"); ?>
</div>
<div id="main">
itemdetails.php
itemdetails.php
<?php
session_start();
include("config.php");
include("functions.php");
$db = mysql_connect($dbhost, $dbuser, $dbpassword);
mysql_select_db($dbdatabase, $db);
$validid = pf_validate_number($_GET[‘id’], "redirect", $config_basedir);
if($_POST[‘submit’]) {
if(is_numeric($_POST[‘bid’]) == FALSE) {
header("Location: " . $config_basedir
. "itemdetails.php?id=" . $validid . "&error=letter");
}
$theitemsql = "SELECT * FROM items WHERE id = " . $validid . ";";
$theitemresult = mysql_query($theitemsql);
$theitemrow = mysql_fetch_assoc($theitemresult);
$checkbidsql = "SELECT item_id, max(amount) AS
highestbid, count(id) AS number_of_bids FROM
bids WHERE item_id=" . $validid . " GROUP BY item_id;";
$checkbidresult = mysql_query($checkbidsql);
$checkbidnumrows = mysql_num_rows($checkbidresult);
if($checkbidnumrows == 0) {
if($theitemrow[‘startingprice’] > $_POST[‘bid’]) {
header("Location: " . $config_basedir
. "itemdetails.php?id=" . $validid . "&error=lowprice#bidbox");
}
}
else {
$checkbidrow = mysql_fetch_assoc($checkbidresult);
if($checkbidrow[‘highestbid’] > $_POST[‘bid’]) {
header("Location: " . $config_basedir . "itemdetails.php?id=" .
$validid . "&error=lowprice#bidbox");
}
}
$inssql = "INSERT INTO bids(item_id, amount, user_id) VALUES("
. $validid
. ", " . $_POST[‘bid’]
. ", " . $_SESSION[‘USERID’]
. ");";
mysql_query($inssql);
header("Location: " . $config_basedir
. "itemdetails.php?id=" . $validid);
}
else {
$validid = pf_validate_number($_GET[‘id’], "redirect",
$config_basedir);
require("header.php");
$itemsql = "SELECT UNIX_TIMESTAMP(dateends) AS dateepoch,
items.* FROM items WHERE id = " . $validid . ";";
$itemresult = mysql_query($itemsql);
$itemrow = mysql_fetch_assoc($itemresult);
$nowepoch = mktime();
$rowepoch = $itemrow[‘dateepoch’];
if($rowepoch > $nowepoch) {
$VALIDAUCTION = 1;
}
echo "<h2>" . $itemrow[‘name’] . "</h2>";
$imagesql = "SELECT * FROM images WHERE item_id = " . $validid . ";";
$imageresult = mysql_query($imagesql);
$imagenumrows = mysql_num_rows($imageresult);
$bidsql = "SELECT item_id, MAX(amount) AS highestbid,
COUNT(id) AS number_of_bids FROM bids WHERE item_id="
. $validid . " GROUP BY item_id;";
$bidresult = mysql_query($bidsql);
$bidnumrows = mysql_num_rows($bidresult);
echo "<p>";
if($bidnumrows == 0) {
echo "<strong>This item has had no bids</strong>
- <strong>Starting Price</strong>: " . $config_currency
. sprintf(‘%.2f’, $itemrow[‘startingprice’]);
}
else {
$bidrow = mysql_fetch_assoc($bidresult);
echo "<strong>Number Of Bids</strong>: "
. $bidrow[‘number_of_bids’] . "
- <strong>Current Price</strong>: " . $config_currency
. sprintf(‘%.2f’, $bidrow[‘highestbid’]);
}
echo " - <strong>Auction ends</strong>: "
. date("D jS F Y g.iA", $rowepoch);
echo "</p>";
if($imagenumrows == 0) {
echo "No images.";
}
else {
while($imagerow = mysql_fetch_assoc($imageresult)) {
echo "<img src=’./images/" . $imagerow[‘name’] ."’ width=’200’>";
}
}
echo "<p>" . nl2br($itemrow[‘description’]) . "</p>";
echo "<a name=’bidbox’>";
echo "<h2>Bid for this item</h2>";
if(isset($_SESSION[‘USERNAME’]) == FALSE) {
echo "To bid, you need to log in. Login
<a href=’login.php?id=" . $validid . "&ref=addbid’>here</a>.";
}
else {
if($VALIDAUCTION == 1) {
echo "Enter the bid amount into the box below.";
echo "<p>";
switch($_GET[‘error’]) {
case "lowprice":
echo "The bid entered is too low.
Please enter another price.";
break;
case "letter":
echo "The value entered is not a number.";
break;
}
?>
<form action="<?php echo pf_script_with_get($SCRIPT_NAME);
?>" method="post">
<table>
<tr>
<td><input type="text" name="bid"></td>
<td><input type="submit" name="submit" value="Bid!"></td>
</tr>
</table>
</form>
<?php
}
else {
echo "This auction has now ended.";
}
$historysql = "SELECT bids.amount, users.username FROM bids,
users WHERE bids.user_id = users.id AND item_id = "
. $validid . " ORDER BY amount DESC";
$historyresult = mysql_query($historysql);
$historynumrows = mysql_num_rows($historyresult);
if($historynumrows >= 1) {
echo "<h2>Bid History</h2>";
echo "<ul>";
while($historyrow = mysql_fetch_assoc($historyresult)) {
echo "<li>" . $historyrow[‘username’] . " - " .
$config_currency . sprintf(‘%.2f’, $historyrow[‘amount’]) . "</li>";
}
echo "</ul>";
}
}
}
require("footer.php");
?>
functions.php
functions.php
<?php
function pf_script_with_get($script) {
$page = $script;
$page = $page . "?";
foreach($_GET as $key => $val) {
$page = $page . $key . "=" . $val . "&";
}
return substr($page, 0, strlen($page)-1);
}
function pf_validate_number($value, $function, $redirect) {
if(isset($value) == TRUE) {
if(is_numeric($value) == FALSE) {
$error = 1;
}
if($error == 1) {
header("Location: " . $redirect);
}
else {
$final = $value;
}
}
else {
if($function == 'redirect') {
header("Location: " . $redirect);
}
if($function == "value") {
$final = 0;
}
}
return $final;
}
?>
推荐答案
您遇到问题
$_GET['id']
你是如何得到这个id的，是来自查询字符串？不要这么认为。使用isset函数检查id是否在url中。所以要解决你的问题，请执行此操作
how are you getting this id, is it coming from query string? Don't think so. Put isset function to check if id is in the url or not. So to solve your problem do this
$validid = 0;
if (isset($_GET['id'])) {
$validid = pf_validate_number($_GET['id'], "value", $config_basedir);
}
将此信息放入index.php
put this in your index.php
这篇关于未定义的索引：php中的id的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
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