嗨，当用户在我的bookingbeforedependent.php文件中单击"删除"时，我正试图删除用户的预订详细信息，但由于某种原因，当我测试我的php文件时，一旦我单击删除，它就会转到我的delete.php屏幕，并表示它无法从数据库中删除，并出现错误Undefined index:rn。我的rn没有定义吗？对不起，我是新手。下面是我的代码：
bookingbeforedependent.php:
<!DOCTYPE HTML>
<html><head><title>BookingBeforeDeletion</title> </head>
<body>
<?php
include "config.php";
$DBC = mysqli_connect("127.0.0.1", DBUSER , DBPASSWORD, DBDATABASE);
if (!$DBC) {
echo "Error: Unable to connect to MySQL.n".
mysqli_connect_errno()."=".mysqli_connect_error() ;
exit;
};
echo "<pre>";
$query = 'SELECT roomname, checkindate, checkoutdate FROM booking';
$result = mysqli_query($DBC,$query);
if (mysqli_num_rows($result) > 0) {
echo "Delete Bookings" ?><p><?php
while ($row = mysqli_fetch_assoc($result)) {
echo "Room name: ".$row['roomname'] . PHP_EOL;
echo "Check in date: ".$row['checkindate'] . PHP_EOL;
echo "Check out date: ".$row['checkoutdate'] . PHP_EOL;
?>
<a href= 'delete.php?rn=$result[roomname]'>Delete</a> <a href="index.php">[Cancel]</a>
<?php
echo "<hr />";
}
mysqli_free_result($result);
}
echo "</pre>";
echo "Connectted via ".mysqli_get_host_info($DBC);
mysqli_close($DBC);
?>
</body>
</html>
delete.php：
<!DOCTYPE HTML>
<html><head><title>BookingBeforeDeletion</title> </head>
body>
<?php
include "config.php";
$DBC = mysqli_connect("127.0.0.1", DBUSER , DBPASSWORD, DBDATABASE);
if (!$DBC) {
echo "Error: Unable to connect to MySQL.n".
mysqli_connect_errno()."=".mysqli_connect_error() ;
exit;
};
echo "<pre>";
$roomname=$_GET['rn'];
$query = "DELETE bookingID, roomname, checkindate, checkoutdate, contactnumber,
bookingextras, roomreview, customerID, roomID FROM booking WHERE roomname =
'$roomname'";
$result = mysqli_query($DBC,$query);
if($result)
{
echo "<font color='green'> Booking deleted from database";
}
else {
echo "<font color='red'> Failed to delete booking from database";
}
?>
我认为这将有所帮助：
- 如上所述，您需要从
PHP打印
<a href= 'delete.php?rn=$result[roomname]'>
// To
<a href= 'delete.php?rn=<?= $row['roomname'] ?>'>
// Explanation:
// 1. <?= ... ?> is the short form of <?php echo ... ?>
// 2. The `roomname` came from $row, not $result ($result is the MySQLi Object)
// 3. You need to quote the `roomname` because without it `roomname` will be readed
// as Constant, and may Throw a Warning message
//
- 您的
DELETE不正确，正确的是DELETE FROM ... WHERE ...
$query = "DELETE bookingID, roomname, checkindate, checkoutdate, contactnumber,
bookingextras, roomreview, customerID, roomID FROM booking WHERE roomname =
'$roomname'";
// To
$query = "DELETE FROM booking WHERE roomname = '$roomname'";
额外：3.您可以为$roomname 指定一个默认值
$roomname=$_GET['rn'];
// To
$roomname=$_GET['rn'] ?? 'default if null';
// if the rn index doesnt exist, the $roomname value will be `default if null` instead of throwing a Warning
- 尝试使用
Prepared-StatementSQL而不是编写它。(我不知道这个例子，但它可以防止SQL注入(