Mysqli如果条件不起作用甚至值匹配

Question

//verify user

if (isset($_POST['dogrula-btn'])) {
    //get variables from the user:
    $token = $_POST['token'];
    //validations:
    if (empty($token)) {
        $errors['token'] = 'Could not be empty!';
    }
    //To avoid display "Wrong credentials" for the first time
    if (count($errors) === 0) {
     $sql = "SELECT * FROM users WHERE token='$token' LIMIT 1";
     $result = $conn->query($sql);

if ($result->num_rows > 0) {
        $row = $result->fetch_assoc();
        $verified= $row['verified'];
        if ($row['verified'] = 0) {
            $update_query = "UPDATE users SET verified = 1 WHERE token = '$token'";
            //using PHP built-in feature to verify the user's input password AND db password
            $_SESSION['id'] = $user['id'];
            $_SESSION['username'] = $user['username'];
            $_SESSION['email'] = $user['email'];
            $_SESSION['verified'] = 1;

            exit();
        } else {
            $errors['token'] = "Already verified!";
        }
    }else{$errors['token'] = "User doesn't exist!";}}
}

数据库“已验证”中的值为0。

即使这样，如果行if ($row['verified'] = 0) { }无法正常工作，并通过else行$ errors ['token'] =“已经验证！”；