Process

<?php
require_once('settings.php');
//Insert name//
$Firstname = $_POST['Firstname'];
$Lastname = $_POST['Lastname'];
$Dob = $_POST['Dob'];
$Gender = $_POST['Gender'];
$Email = $_POST['Email'];
$Phone = $_POST['Phone'];
$Address = $_POST['Address'];
$Suburb = $_POST['Suburb'];
$State = $_POST['State'];
$Postcode = $_POST['Postcode'];
$Job_prefer = $_POST['Job_prefer'];
$Job_reference_number = $_POST['Job_reference_number'];

// Convert arrays to strings
    if (is_array($_POST['Programming_Language']) && !empty($_POST['Programming_Language'])) {
   $Programming_language = implode(",", $_POST['Programming_Language']);
    } else {
     $Programming_language = ""; 
 }

    if (is_array($_POST['Skills']) && !empty($_POST['Skills'])) {
     $Skills = implode(",", $_POST['Skills']);
     } else {
     $Skills = "";  
 }
//connection//
$con = mysqli_connect($host, $user, $pwd, $sql_db);

if(mysqli_connect_errno()){
    echo "$con->connect_error";
    die("Connection Failed : ". mysqli_connect_error());
} 
    $sql="insert into ApplyForm_Assignment2(Firstname, Lastname, Dob, Gender, Email, Phone, Address, Suburb, State, Postcode, Job_prefer, Job_reference_number, Programming_Language, Skills) values(?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)";
    $result= mysqli_connect($con,$sql);
    $stmt = mysqli_stmt_init($con);
    if (!mysqli_stmt_prepare($stmt,$sql)){
        die(mysqli_error($con));
    }   
    mysqli_stmt_bind_param($stmt, "ssssssssssssss", $Firstname, $Lastname, $Dob, $Gender, $Email, $Phone, $Address, $Suburb, $State, $Postcode, $Job_prefer, $Job_reference_number, $Programming_language, $Skills);
    mysqli_stmt_execute($stmt);
    if ($result) {
        // Assuming $con is a valid MySQLi database connection
        $last_id = mysqli_insert_id($con); // Get the last inserted ID
    
        if ($last_id) {
            $code = rand(1, 99999);
            $User_ID = "FIVE_" . $code . "_" . $last_id;
    
            // Use prepared statements to update the record
            $query = "UPDATE ApplyForm_Assignment2 SET User_ID = ? WHERE id = ?";
            $stmt = mysqli_prepare($con, $query);
            
            if ($stmt) {
                // Bind parameters and execute the query
                mysqli_stmt_bind_param($stmt, "si", $User_ID, $last_id);
                $res = mysqli_stmt_execute($stmt);
                
                if ($res) {
                    echo "Update successful, User_ID is: " . $User_ID;
                } else {
                    echo "Error updating record: " . mysqli_error($con);
                }
    
                mysqli_stmt_close($stmt);
            } else {
                echo "Error preparing statement: " . mysqli_error($con);
            }
        } else {
            echo "No last ID found";
        }
    } else {
        echo "Error in the initial query: " . mysqli_error($con);
    }
    
echo "<p class='mycss'> Sending successfully.</p>";
?>