将数据从下拉列表保存到数据库CakePHP

I'm new to the CakePhp framework and currently i'm testing out a project. Issue i have is, i can populate the dropdown option but when i want to select an option it won't get saved on the database. Did i miss something?

Using this code i can populate the drop down - bookings.js

    $("#contact_submit").click(function () {

    var name = $("#name").val();
    var contact_email = $("#contact_email").val();
    var subject = $("#subject").val();
    var message = $("#txtmessage").val();
    var service = $("#sel1").val();

    console.log(name+contact_email+subject+message+service);

    $.post("/inquiries/inquiry", //Required URL of the page on server
            {// Data Sending With Request To Server
                name: name,
                email: contact_email,
                subject: subject,
                txt: message,
                service_id: service,
            },
            function (response) { // Required Callback Function
            if (jQuery.parseJSON(response).status == 'success') {
            if ($("#available").hasClass("hide")) {
                $("#available").removeClass("hide");
            }
            if (!$("#available").hasClass("hide")) {
                $("#notavailable").addClass("hide");
            }

            }else{
            if ($("#notavailable").hasClass("hide")) {
                $("#notavailable").removeClass("hide");
            }
            if (!$("#available").hasClass("hide")) {
                $("#available").addClass("hide");
            }
            }
            });
});

InquriesController.php

    public function inquiry()
     {
    $inquiry = $this->Inquiries->newEntity();
    if ($this->request->is('post')) {

    $emailaddress = $this->request->data['email'];
    $subject = $this->request->data['subject'];
    $txt = $this->request->data['txt'];
    $services = $this->request->data['service_id'];
    $message = "this is a message"; 
    $inquiry = $this->Inquiries->patchEntity($inquiry, $this->request->data);

        if ($this->Inquiries->save($inquiry)) {

        $email = new Email('default');
        $email->from(['myemail@gmail.com' => 'Testing Hotel'])
        ->to($emailaddress)
        ->subject('Inquiry Mail')
        ->emailFormat('html')
        ->send($message);

        echo json_encode(['status' => 'success']);
        exit; 

        } else {

        echo json_encode(['status' => 'failed']);
        exit;  

        }
    }

}

HTML CODE SNIPPET

        <div class="col-md-6 col-sm-6 col-xs-12">
            <input type="text" name="contact_email" id="contact_email" class="form-control" placeholder="Email *"> 
        </div>
        <div class="col-md-12 col-sm-12 col-xs-12">
            <input type="text" id="subject" class="form-control" placeholder="Subject"> 
        </div>
        <div class="col-md-12 col-sm-12 col-xs-12">

            <input class="form-control" name="txtmessage" id="txtmessage" rows="8" placeholder="Messages goes here.."></input>

            <div class="form-group">
                <select class="form-control" id="sel1">
                    <option>Select a service</option>
                    <?php
                      if (!empty($ServicesInfo)) { 
                          foreach ($ServicesInfo as $Services):        
                            ?> 
                        <option value="<?=  h($Services->name)?>"><?=  h($Services->name)?></option>
                    <?php endforeach;  } ?> 
                </select>
            </div>

As i told you, your int field in the table cannot save the varchar of service name. So, you need to send the service id as value from the select option. Like so :

<option value="<?= h($Services->id)?>"><?= h($Services->name)?></option>