SQLSTATE[42000]:语法错误或访问冲突:1064

我现在正在编写一些软件。读者摘要版本：用户选择一个包，输入他们的姓名、电子邮件和所需的子域。然后检查子域以查看是否有人已经注册了它，以及它是否只是字母数字。我使用OO mysqli完成了所有这些工作，但是我决定迁移到PDO。

错误的确切措辞：

SQLSTATE[42000]：语法错误或访问冲突：1064 您的 SQL 语法有错误;请查看与您的 MySQL 服务器版本对应的手册，了解在第 1 行的"->子域"附近使用的正确语法

当我开始实例化我的 Admin 对象时，一切都很好。但是，当我调用createAccount()函数时，所有的地狱都松动了。堆栈跟踪到处都是，我几乎不知道何时开始对此进行故障排除。我在这里检查了其他答案，它们似乎都太本地化了，所以这里是生成它的代码，然后是所有包含错误的方法。来吧。。。。

首先，产生错误的代码：

include 'classes/Admin.class.php';
$admin = new Admin('test@test.com');
try {
    $admin->createAccount('John', 'Smith', 'test', 'pro');
}
catch(Exception $e) {
    echo '<pre />';
    echo $e->getMessage();
    die(print_r($e->getTrace()));
}

管理员类构造函数

public function __construct($email) {
        $this->email = $email;
        include 'Database.class.php';
        include 'PasswordHash.php';
        define("DB_HOST", "localhost");
        define("DB_USER", "root");
        define("DB_PASS", "");
        define("DB_NAME", "ems");
        $this->data = new Database;
        $this->hasher = new PasswordHash(8, false);
    }

在Admin类中，检查子域

private function checkSubdomain() {
    $this->data->query('SELECT * FROM clients WHERE subdomain = :subdomain');
    $this->data->bind(':subdomain', $this->subdomain);
    $this->data->execute();
    return ($this->data->rowCount() == 0) && (ctype_alnum($this->subdomain));
}

PDO 类执行、绑定和查询

public function execute() {
    return $this->stmt->execute();
}
public function query($query) {
    $this->stmt = $this->dbh->prepare($query);
}
public function bind($param, $value, $type = null) {
    if(is_null($type)) {
        switch(true) {
            case is_int($value):
                $type = PDO::PARAM_INT;
                break;
            case is_bool($value):
                $type = PDO::PARAM_BOOL;
                break;
            case is_null($value):
                $type = PDO::PARAM_NULL;
            default:
                $type = PDO::PARAM_STR;
        }
    }
    $this->stmt->bindValue($param, $value, $type);
}

这个错误在我的代码中很普遍，所以我认为它只在 PDO 类中，但我的 Session 类工作得很好。此外，我的查询仅使用 mysqli 即可完美运行，因此我对自己的语法充满信心。任何帮助将不胜感激。

根据请求，创建帐户功能：

public function createAccount($firstname, $lastname, $subdomain, $package)
{
    $this->firstname = $firstname;
    $this->lastname  = $lastname;
    $this->subdomain = $subdomain;
    $this->package   = $package;
    //does the subdomain exist, or is it invalid?
    if(!$this->checkSubdomain())
        throw new Exception('This domain is not available. It can only contain letters and numbers and must not already be taken.');
    //now comes the table creation, provided everything is in order
    $this->setup();
}

下面是由createAccount调用的设置函数(没有所有表结构(：

private function setup() {
    $isError = false;
    $queries = array(
        //all of these are CREATE statements, removed for security reasons
        );
    //need a database that matches with the client subdomain
    $this->data->query('CREATE TABLE $this->subdomain');
    $this->data->bind(':subdomain', $this->subdomain);
    //PDO secured...execute
    $this->data->execute();
    $this->data->beginTransaction();
    foreach($queries as $query) {
        $this->data->query($query);
        if(!$this->data->execute()) { //we hit some sort of error, time to GTFO of here
            $isError = true;
            $this->data->cancelTransaction();
            //die('Error with: ' . $query);
            break;
        }
    }
    if(!$isError) {
        $this->data->endTransaction();
        mkdir('a/' . $this->subdomain, 0755);
        $this->generatePass();
        //this is where I insert the user into the admin table using PDO, removed for security
        $this->data->execute();
    }
    $this->data->close();
}

$this->data->query('CREATE TABLE $this->subdomain');
$this->data->bind(':subdomain', $this->subdomain);

if (preg_match('/^['w_]+$/i', $this->subdomain)) {
    // note the ` (backtick), and using " (double quotes):
    $this->data->query("CREATE TABLE `{$this->subdomain}`"); 
} else {
    // throw exception or error, do not continue with creating table
}

$a = 1;
$b = 2;
echo '$a + $b'; // outputs: $a + $b
echo "$a + $b"; // outputs: 1 + 2
$c = array(5, 10);
echo ''$c[0] = {$c[0]}'; // outputs: '$c[0] = {$c[0]}
echo "'$c[0] = {$c[0]}"; // outputs: $c[0] = 5

    $stmt = $dbh->query(
    'SELECT ' . $userfield . ' FROM ' . $usertable . ' WHERE 1 '
    );
    $results = $stmt->fetchAll(PDO::FETCH_ASSOC);