php - MySQL 语法 :You have an error in your SQL syntax…

Question

我从下面的代码中收到以下错误。

您的 SQL 语法有误；查看与您的 MySQL 服务器版本对应的手册，了解在第 1 行的“@doe.com,username,5f4dcc3b5aa765d61d8327deb882cf99,09/05/2011 1:11:13 AM)”附近使用的正确语法

$username = $_GET['username'];
$password = md5($_GET['password']);
$firstname = $_GET['firstname'];
$lastname = $_GET['lastname'];
$email = $_GET['email'];
$date = uk_date();
$conn = mysql_connect('localhost', 'myuser', 'mypass');
mysql_select_db('dbname');
$query = "INSERT INTO accounts (FirstName, LastName, Email, Username, Password, LastLoginDate) VALUES (". $firstname . ",". $lastname ."," . $email . "," . $username . "," . $password . "," . $date . ")";
$result = mysql_query($query) or die(mysql_error());
echo 'Success';
mysql_close($result);

你能告诉我我的问题是什么吗？我是 MySQL 和 PHP 的新手，所以请您解释一下我做错了什么以供以后引用。

Answer 1

您没有在 INSERT 中引用任何值，您应该这样说:

$query = "INSERT INTO accounts (FirstName, LastName, Email, Username, Password, LastLoginDate) VALUES ('". $firstname . "','". $lastname ."','" . $email . "','" . $username . "','" . $password . "','" . $date . "')";

您还应该使用 mysql_real_escape_string在所有这些变量上，以确保任何嵌入的引号等都被正确编码。

更好的版本应该是这样的:

$query = sprintf("INSERT INTO accounts (FirstName, LastName, Email, Username, Password, LastLoginDate) VALUES ('%s', '%s', '%s', '%s', '%s', '%s')",
    mysql_real_escape_string($firstname),
    mysql_real_escape_string($lastname),
    mysql_real_escape_string($email),
    mysql_real_escape_string($username),
    mysql_real_escape_string($password),
    mysql_real_escape_string($date));

您还应该收听 BoltClock 并使用 PDO和占位符，这样您就不必担心引号和转义太多。 PDO 还将使切换数据库变得更加容易。