Need help redirecting through PHP - php

Question

I'm currently building a survey. I've made quite a bit of progress so far. If a participant completes and submits the survey it successfully enters my database and returns the participant to the main page of my site but if one question is skipped by the participant, when they try to submit the survey it returns a blank display and no data is fed into my database.
I want to create a survey that gives participants the ability to skip questions, and returns them to the homepage after submitting the survey.
I understand it may be easy for some but I'm fairly new to PHP so I'm still learning, please see the code below.
<?php
$radioVal1 = $_POST["q1"];
$radioVal2 = $_POST["q2"];
$radioVal3 = $_POST["q3"];
$radioVal4 = $_POST["q4"];
$radioVal5 = $_POST["q5"];
$checkboxVal6 = $_POST["q6"];
$textAreaVal = $_POST["comment"];
session_start();
require_once('DBConnection.php');
if(isset($_POST["submit_questionnaire"])){
if(isset($_POST["q1"]) && isset($_POST["q2"]) && isset($_POST["q3"]) && isset($_POST["q4"]) && isset($_POST["q5"]) && isset($_POST["q6"]) && $textAreaVal!=null){
echo "blyat";
$username = $_SESSION['username'];
$db = new DBConnection();
$conn= $db::getInstance()->dbConnect();
$query_code = "SELECT id_code FROM users WHERE name = '$username'";
$id_codeRow = $db::getInstance()->selectDB($query_code)->fetch_row();
$id_code = (string)array_values($id_codeRow)[0];
$query = "INSERT INTO questionnaire VALUES (default, '$id_code', '$radioVal1', '$radioVal2', '$radioVal3','$radioVal4', '$radioVal5', '$checkboxVal6', '$textAreaVal')";
$insert_value = $db::getInstance()->selectDB($query);
session_destroy();
header("Location: index.php");
exit();
}
}

Answer 1

// You can remplace "&&" by "OR" so any questions can be skipped by the user but the user have to complete atleast 1 question.
<?php
$radioVal1 = $_POST["q1"];
$radioVal2 = $_POST["q2"];
$radioVal3 = $_POST["q3"];
$radioVal4 = $_POST["q4"];
$radioVal5 = $_POST["q5"];
$checkboxVal6 = $_POST["q6"];
$textAreaVal = $_POST["comment"];
session_start();
require_once('DBConnection.php');
if(isset($_POST["submit_questionnaire"])){
if(isset($_POST["q1"]) OR isset($_POST["q2"]) OR isset($_POST["q3"]) OR isset($_POST["q4"]) OR isset($_POST["q5"]) OR isset($_POST["q6"])){
echo "blyat";
$username = $_SESSION['username'];
$db = new DBConnection();
$conn= $db::getInstance()->dbConnect();
$query_code = "SELECT id_code FROM users WHERE name = '$username'";
$id_codeRow = $db::getInstance()->selectDB($query_code)->fetch_row();
$id_code = (string)array_values($id_codeRow)[0];
$query = "INSERT INTO questionnaire VALUES (default, '$id_code', '$radioVal1', '$radioVal2', '$radioVal3','$radioVal4', '$radioVal5', '$checkboxVal6', '$textAreaVal')";
$insert_value = $db::getInstance()->selectDB($query);
session_destroy();
header("Location: index.php");
exit();
}
}