问如何解决使用php将所选选项存储到数据库中错误

EN

<form id="contact-form" method="post" action="ticketSupport.php" role="form">
    <div class="messages"></div>
    <div class="controls">
        <div class="row">
            <div class="col-md-6">
                <div class="form-group">
                    <label for="form_item_select" class="mbr-white text-center">Select item <span class="text-red">*</span></label>
                    <select id="form_item_select" name="item_select" class="custom-select" required="required" data-error="Please specify your need.">
                        <option>Select item</option>
                        <option value="theme1">Example template (1)</option>
                        <option value="theme2">Example 2 template (5)</option>
                        <option value="theme3">Example 3 template (15)</option>
                    </select>
                    <div class="help-block with-errors"></div>
                </div>
            </div>
            <div class="col-md-6">
                <div class="form-group">
                    <label for="form_help_select" class="mbr-white text-center">Help topic <span class="text-red">*</span></label>
                    <select id="form_help_select" name="help_selected" class="custom-select" required="required" data-error="Please specify your need.">
                        <option>Select help topic</option>
                        <option value="Feedback">Feedback</option>
                        <option value="General inquiry">General inquiry</option>
                        <option value="Report a problem">Report a problem</option>
                        <option value="Report a problem / Access Issue">Report a problem / Access Issue</option>
                    </select>
                    <div class="help-block with-errors"></div>
                </div>
            </div>
        </div>
        <div class="row">
            <div class="col-md-6">
                <div class="form-group">
                    <label for="form_email" class="mbr-white text-center">Email <span class="text-red">*</span></label>
                    <input id="form_email" type="email" name="email" class="form-control" readonly placeholder="Please enter your email *" required="required" data-error="Valid email is required." value="<?php echo $userData['email']; ?>">
                    <div class="help-block with-errors"></div>
                </div>
            </div>
            <div class="col-md-6">
                <div class="form-group">
                    <label for="form_phone" class="mbr-white text-center">Phone number</label>
                    <input id="form_phone" type="text" name="phone" class="form-control" readonly placeholder="Please enter your phone number *" required="required" data-error="Valid phone is required." value="<?php echo $userData['phone']; ?>">
                    <div class="help-block with-errors"></div>
                </div>
            </div>
        </div>
        <div class="row">
            <div class="col-md-12">
                <div class="form-group">
                    <label for="form_message" class="mbr-white text-center">Ticet details <span class="text-red">*</span></label>
                    <p class="mbr-white small">Please describe your issue</p>
                    <textarea id="form_message" name="message" class="form-control" placeholder="Details on the reason(s) for opening the ticket. *" rows="4" required="required" data-error="Please, leave us a message."></textarea>
                    <div class="help-block with-errors"></div>
                </div>
            </div>
            <div class="col-md-12">
                <input type="submit" class="btn btn-primary btn-block sgn" value="Create ticket">
            </div>
        </div>
    </div>
</form>

<?php
$servername = "localhost";
$username = "root";
$password = "";
$dbname = "db_name";

try {
$conn = new PDO("mysql:host=$servername;dbname=$dbname", $username,
    $password);
// set the PDO error mode to exception
$conn->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);

// prepare sql and bind parameters
$stmt = $conn->prepare("INSERT INTO tickets (item_selected, help_selected, 
email, phone, message) 
VALUES (:item_selected, :help_selected, :email, :phone, :message)");
$stmt->bindParam(':item_selected', $item_selected);
$stmt->bindParam(':help_selected', $help_selected);
$stmt->bindParam(':email', $email);
$stmt->bindParam(':phone', $phone);
$stmt->bindParam(':message', $message);

// insert a row
$item_selected = $_POST["item_selected"];
$help_selected = $_POST["help_selected"];
$email = $_POST["email"];
$phone = $_POST["phone"];
$message = $_POST["message"];
$stmt->execute();


header('Location: ticket-status');
}
catch(PDOException $e)
{
echo "Error: " . $e->getMessage();
}
$conn = null;
?>