我一直在尝试创建一个登录页面，我只需在其中登录和注销。我似乎总是出错。这一次，我使用了一个脚本，在第 15 行和第 16 行出现错误，并且一直显示“注意:未定义索引:C:\xampp\htdocs\phpstuff\main_login.php 中的 $myusername 在第 15 行
注意: undefined index :C:\xampp\htdocs\phpstuff\main_login.php 中的 $mypassword 第 16 行
错误的用户名或密码”当我什至没有输入密码或用户名时。我是新手，所以如果你能帮助我，那就太好了。这是我所有的代码。
main_login.php:
<?php
ob_start();
$host="localhost"; // Host name
$username="root"; // Mysql username
$password=""; // Mysql password
$db_name="lordhelpme"; // Database name
$tbl_name="members"; // Table name
// Connect to server and select databse.
mysql_connect("$host", "$username", "$password")or die("cannot connect");
mysql_select_db("$db_name")or die("cannot select DB");
// Define $myusername and $mypassword
$myusername=$_POST['myusername'];
$mypassword=$_POST['mypassword'];
// To protect MySQL injection (more detail about MySQL injection)
$myusername = stripslashes($myusername);
$mypassword = stripslashes($mypassword);
$myusername = mysql_real_escape_string($myusername);
$mypassword = mysql_real_escape_string($mypassword);
$sql="SELECT * FROM $tbl_name WHERE username='$myusername' and password='$mypassword'";
$result=mysql_query($sql);
// Mysql_num_row is counting table row
$count=mysql_num_rows($result);
// If result matched $myusername and $mypassword, table row must be 1 row
if($count==1){
// Register $myusername, $mypassword and redirect to file "login_success.php"
session_register("myusername");
session_register("mypassword");
header("location:login_success.php");
}
else {
echo "Wrong Username or Password";
}
ob_end_flush();
?>
<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>Untitled Document</title>
</head>
<body>
<table width="300" border="0" align="center" cellpadding="0" cellspacing="1" bgcolor="#CCCCCC">
<tr>
<form name="form1" method="post" action="checklogin.php">
<td>
<table width="100%" border="0" cellpadding="3" cellspacing="1" bgcolor="#FFFFFF">
<tr>
<td colspan="3"><strong>Member Login </strong></td>
</tr>
<tr>
<td width="78">Username</td>
<td width="6">:</td>
<td width="294"><input name="myusername" type="text" id="myusername"></td>
</tr>
<tr>
<td>Password</td>
<td>:</td>
<td><input name="mypassword" type="text" id="mypassword"></td>
</tr>
<tr>
<td> </td>
<td> </td>
<td><input type="submit" name="Submit" value="Login"></td>
</tr>
</table>
</td>
</form>
</tr>
</table>
</body>
</html>
最佳答案
删除 $ 符号:
$myusername=$_POST['myusername'];
$mypassword=$_POST['mypassword'];
http://www.php.net/manual/en/reserved.variables.post.php
另外，这里不需要引号:
mysql_connect($host, $username, $password)or die("cannot connect");
mysql_select_db($db_name)or die("cannot select DB");
您使用的是变量，而不是文字。
关于php - undefined index $myusername 和 $mypassword？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/20873377/