没有引发任何错误，但是数据库中没有任何变化

Question

它可以在我的本地主机上运行，​​但不能在服务器上运行。这是否意味着数据库根本没有连接，还是语句中出现错误？

$submission = $_POST['submit'];
$decode = json_decode($submission, true);

try {
    $pdo = new PDO('mysql:localhost;dbname=database', 'username', 'password');

} catch(PDOException $e){
    echo 'PDO Exception: '.$e->getMessage();
    die();
}

class QueryBuilder {
    protected $pdo;
    public function __construct($pdo){
        $this->pdo = $pdo;
    }

    public function insert($parameters){
        $sql = "insert into tableName ('entry', 'author', 'email', 'sign', 'month') values (:entry, :author, :email, :sign, :month)";
        $statement = $this->pdo->prepare($sql);
        try {
            $statement->execute($parameters);
        } catch (Exception $e) {
            die($e->getMessage());
        }
    }
}

$query = new QueryBuilder($pdo);
$query->insert($decode);

我什至尝试了一个表清除语句，它也无济于事...

public function clear(){
    try {
        $statement = $this->pdo->prepare("truncate table submissions");
        $statement->execute();
    } catch (Exception $e) {
        die($e->getMessage());
    }
}

$query->clear();