How to insert multiple checkbox value in a single column of MySQL using PHP

Here we using 2 file for insert multiple checkbox value:


<!DOCTYPE html>

<form method="post" action="process.php">
<input type="checkbox" name="vehicle[]" value="Bike">I have a bike
<input type="checkbox" name="vehicle[]" value="Cycle">I have a Cycle
<input type="checkbox" name="vehicle[]" value="Car">I have a car 
<input type="submit" value="Submit">



$username = "root";
$password = "";
$dbname = "admin";
$checkbox1 = $_POST['vehicle'];
    foreach($checkbox1 as $chk1)  
          $chk.= $chk1.",";  

$conn = mysqli_connect($url, $username, $password, $dbname);
if (!$conn) {
    die("Connection failed: " . mysqli_connect_error());
$sql = "INSERT INTO checkbox(vehicle)VALUES( '$chk' )";

if(mysqli_query($conn,$sql)) {

    echo 'Data added sucessfully';
else {
    echo "Error: " . $sql . "<br>" . mysqli_error($conn);