我正在尝试为我的数据库创建一个电子邮件验证表单，但是我遇到了很多问题。当我尝试运行下面的代码时，我得到错误没有选择数据库。
我也得到一个未定义的变量错误。我希望将用户名放在用户名字段下的数据库中，但显然$ name是一个未定义的变量。 xx未定义变量mysql_query("INSERT INTO registrations (username, password, email, hash) VALUES( '". mysql_real_escape_string($name) ."',上的错误。
我正在使用WAMP服务器。数据库的名称是sitememberdetails，以及该名称 表我需要输入的信息是注册。我对此很新 - 有人能告诉我如何定义变量以及我如何选择数据库（尽管它似乎已经被选中了？）
<?php
$host = "localhost";
$username = "";
$password = "";
$databasename = "sitememberdetails";
$email="xxxxxx@xxxxxxxx.xxx";
$connection = mysql_connect($host,$username,$password) or die
("Error: ".mysql_error());
mysql_select_db($databasename);("sitememberdetails") or
die(mysql_error());
if(isset($_POST['name']) && !empty($_POST['name']) AND
isset($_POST['email']) && !empty($_POST['email'])){
$name = mysql_real_escape_string($_POST['name']);
$email = mysql_real_escape_string($_POST['email']); }
if(!preg_match("/^[_a-z0-9-]+(\.[_a-z0-9-]+)*@[a-z0-9-]+(\.[a-
z0-9-]+)*(\.[a-z]{2,3})$/i", $email)){
$msg = 'The email you have entered is invalid, please try again.';
}else{
$msg = 'Your account has been made, <br /> please verify it
by clicking the activation link that has been send to
your email.';
}
$hash = md5( rand(0,1000) );
$password = rand(1000,5000);
mysql_query("INSERT INTO registrations (username, password,
email, hash) VALUES(
'". mysql_real_escape_string($name) ."',
'". mysql_real_escape_string(md5($password)) ."',
'". mysql_real_escape_string($email) ."',
'". mysql_real_escape_string($hash) ."') ") or
die(mysql_error());
$to = $email; // Send email to our user
$subject = 'Signup | Verification'; // Give the email a subject
$message = '
Thanks for signing up!
Your account has been created, you can login with the following
credentials after you have activated your account by pressing
the url below.
Username: '.$name.'
Password: '.$password.'
Please click this link to activate your account:
http://www.yourwebsite.com/verify.php?email='.$email.'&
hash='.$hash.'
';
$headers = 'From:noreply@yourwebsite.com' . "\r\n"; // Set from
headers
mail($to, $subject, $message, $headers); // Send our email
?>
答案 0 :(得分：1)
尝试更改此代码
mysql_select_db($databasename);("sitememberdetails") or
die(mysql_error());
到这个
mysql_select_db($databasename) or die(mysql_error());
EOL;
if (database_connection) {
unset($undefined_variable_error)
} else {
echo $undefined_variable_error;
}
// Because mysql_real_escape_string needs an open mysql connection
答案 1 :(得分：1)
查看此修改后的代码：
<?php
$host = "localhost";
$username = "";
$password = "";
$databasename = "sitememberdetails";
$email="xxxxxx@xxxxxxxx.xxx";
$connection = mysql_connect($host,$username,$password) or die ("Error: ".mysql_error());
mysql_select_db($databasename) or die(mysql_error());
$name = "";
if(isset($_POST['name']) && !empty($_POST['name']) AND
isset($_POST['email']) && !empty($_POST['email'])){
$name = mysql_real_escape_string($_POST['name']);
$email = mysql_real_escape_string($_POST['email']); }
if(!preg_match("/^[_a-z0-9-]+(\.[_a-z0-9-]+)*@[a-z0-9-]+(\.[a-z0-9-]+)*(\.[a-z]{2,3})$/i", $email)){
$msg = 'The email you have entered is invalid, please try again.'; }
else {
$msg = 'Your account has been made, <br /> please verify it
by clicking the activation link that has been send to your email.';
}
$hash = md5( rand(0,1000) );
$password = rand(1000,5000);
mysql_query("INSERT INTO registrations (username, password,email, hash) VALUES(
'". mysql_real_escape_string($name) ."',
'". mysql_real_escape_string(md5($password)) ."',
'". mysql_real_escape_string($email) ."',
'". mysql_real_escape_string($hash) ."') ") or die(mysql_error());
$to = $email; // Send email to our user
$subject = 'Signup | Verification'; // Give the email a subject
$message = ' Thanks for signing up!
Your account has been created, you can login with the following
credentials after you have activated your account by pressing
the url below.
Username: '.$name.'
Password: '.$password.'
Please click this link to activate your account:
http://www.yourwebsite.com/verify.php?email='.$email.'&
hash='.$hash.'
';
$headers = 'From:noreply@yourwebsite.com' . "\r\n"; // Set from
mail($to, $subject, $message, $headers); // Send our email
?>
我建议您使用PDO而不是mysql_ functions
答案 2 :(得分：0)
似乎$ name值未发布到表单中。如果名称变量已设置且不为空，那么你是mysql_escaping名称变量，但是如果没有设置名称变量会发生什么？没有对此进行检查，因此它一直持续到它进入INSERT语句并导致错误。
查看示例＃1 here以选择数据库。你有一个分号（$ databasename）;没有意义。
答案 3 :(得分：0)
这是一些修改后的代码，使用PDO而不是mysql_ *。让我知道这个是否有效，我们可以解决任何问题。
<?php
$host = 'localhost';
$dbname = 'sitememberdetails';
$user = '';
$pass = '';
try
{
$DB = new PDO("mysql:host=$host;dbname=$dbname", $user, $pass);
}
catch(PDOException $e)
{
echo $e->getMessage();
}
if(isset($_POST['name']) && !empty($_POST['name']) AND isset($_POST['email']) && !empty($_POST['email']))
{
$name = $_POST['name'];
$email = $_POST['email'];
}
else
{
$name = 'No Name';
$email = 'No Email';
}
if(!preg_match("/^[_a-z0-9-]+(\.[_a-z0-9-]+)*@[a-z0-9-]+(\.[a-z0-9-]+)*(\.[a-z]{2,3})$/i", $email))
{
$msg = 'The email you have entered is invalid, please try again.';
}else{
$msg = 'Your account has been made, <br /> please verify it by clicking the activation link that has been send to your email.';
}
$hash = md5( rand(0,1000) );
$password = rand(1000,5000);
$query = "INSERT INTO registrations (username, password, email, hash) VALUES('?', '?', '?', '?')";
$sth = $DB->prepare($query);
//By using ?'s and prepare/execute, PDO will prevent SQL Injection for you!
$sth->execute(array($name, md5($password), $email, $hash));
$to = $email; // Send email to our user
$subject = 'Signup | Verification'; // Give the email a subject
$message = 'Thanks for signing up! Your account has been created,
you can login with the following credentials after you
have activated your account by pressing the url below.
Username: '.$name.'
Password: '.$password.'
Please click this link to activate your account:
http://www.yourwebsite.com/verify.php?email='.$email.'&
hash='.$hash;
$headers = 'From:noreply@yourwebsite.com' . "\r\n"; // Set from header
mail($to, $subject, $message, $headers); // Send our email
?>