我正在尝试解决一个应用程序的问题。最初，由于php从php5升级到php7，我们遇到了问题。这似乎在某些地方得到了纠正，但现在我又遇到了问题。
有人能检查一下语法，看看输入是否正确吗？

if($_POST['create_special_appointment']){ 
    $customer_id   = htmlspecialchars($_POST['customer'], ENT_QUOTES);
    $category_id   = htmlspecialchars($_POST['category'], ENT_QUOTES);
    $start_date    = htmlspecialchars($_POST['start_date'], ENT_QUOTES);
    $end_date      = htmlspecialchars($_POST['end_date'], ENT_QUOTES);
    $start_time = htmlspecialchars($_POST['start_time'], ENT_QUOTES);
    $end_time   = htmlspecialchars($_POST['end_time'], ENT_QUOTES);
    $booked_for =  post_array_to_explode($_POST['booked_for']);
    $notes      = htmlspecialchars($_POST['notes'], ENT_QUOTES);
    $session_id = htmlspecialchars($_POST['session_id'], ENT_QUOTES);
    $time       = date("Y-m-d H:i:s");
    $agent_id   = get_agent_from_session($session_id, 'id');

    //if(!($start_time)){$start_time = '00:00';}
    //if(!($end_time)){$end_time = '00:00';}
    //$start_date = $start_date.' '.$start_time;
    //$end_date = $end_date.' '.$end_time;

    $date=date('Y-m-d',strtotime($date));
    $start_date = $start_date.' '.$start_time.":00";
    $end_date = $end_date.' '.$end_time.":00";

    //$start_date = format_datetime_mysql($start_date);
    //$end_date = format_datetime_mysql($end_date);

    $insert = $dbh->exec("INSERT INTO calendar_special(start_date, end_date, notes, category_special_id, added_by, booked_for, date_added, customer_id) VALUES ('$start_date', '$end_date', '$notes', '$category_id', '$agent_id', '$booked_for', '$time', '$customer_id')");
    if($insert){
        $notification_msg[] = array(type=>'alert-success', h4=>'Success!', msg=>'Appointment Created');
        header('Location: ' . $_SERVER['HTTP_REFERER']);
    }else{
        $notification_msg[] = array(type=>'alert-warning', h4=>'Warning!', msg=>'Appointment NOT Created');
        mysqli_error($con);
        var_dump($_REQUEST);
        print_r($dbh->errorInfo());
    }
    //temp-code
    //var_dump($insert);
}

实际形式代码为：

<select name="customer" id="customer-single" style="width:100%"> 
        <option value="">Select a customer (Optional)</option>
        <?php  foreach(customer_array($ajax['0']) as $customer){ ?>
            <option value="<?php echo $customer['id'] ?>">
        <?php echo $customer['business_name'] ?> - <?php echo $customer['first_name'] ?> <?php echo $customer['last_name'] ?></option>
        <?php } ?>
</select>

我得到的错误是：
“警告！“未创建约会”
数组（11）{[“会话id”]=>字符串（64）“c5ec66786328e97af8f8fb6771912b58c5869986816b3d2bc9916b7e740cff44”[“创建特殊约会”]=>字符串（4）“真”[“客户”]=>字符串（0）”[“类别”]=>字符串（1）“1”[“开始日期”]=>字符串（10）“2018-10-23”[“开始时间”]=>字符串（5）“10:35”[“结束日期”]=>字符串（10）“2018-10-31”[“结束时间”]=>string（5）“10:35”[“booked\u by”]=>string（1）“5”[“booked\u for”]=>数组（1）{[0]=>string（2）“71”}[“notes”]=>string（18）“paul holiday test”}数组（[0]=>22007[1]=>1366[2]=>第1行“customer\u id”列的整数值“”不正确）
抱歉，如果这个问题的措辞有误，如果是这样，请告知。