valid_join.php

<?php
session_start();
if (!isset($_POST['username'])){
    exit("this page is not displayable");
}

require_once("sql_connect.php");
    $fname = mysqli_real_escape_string($conn, $_POST['username']);
    $femail = mysqli_real_escape_string($conn, $_POST['email']);
    $pwd = mysqli_real_escape_string($conn, $_POST['password']);
    $fdob = mysqli_real_escape_string($conn, $_POST['dob']);
    $fgender = mysqli_real_escape_string($conn, $_POST['gender']);
    $pnumber = mysqli_real_escape_string($conn, $_POST['phonenumber']);
    $uID = mysqli_real_escape_string($conn, $_POST['userid']);
    $grant = mysqli_real_escape_string($conn, "allow");

    if (!filter_var($femail, FILTER_VALIDATE_EMAIL)) {
        exit("Invalid email!");
    }
    $sql1= mysqli_query($conn, "SELECT userID FROM users where userID='{$uID}'");
    if (mysqli_num_rows($sql1) > 0){
    exit("ID already taken try another one!");
    }
    $sql1= mysqli_query($conn, "SELECT userID FROM users where email='{$femail}'");
    if (mysqli_num_rows($sql1) > 0){
    exit("email already taken try another one!");
    }
    //upload the FORM to mysql db
    $data = $conn->prepare("INSERT INTO users(userID, username, email,password, date_of_birth, gender, phonenumber,all_map_access)VALUES(?, ?, ?, ?, ?, ?,?,?)");
    $data->bind_param("ssssssss", $uID, $fname, $femail, $pwd, $fdob, $fgender, $pnumber, $grant);
   
    $data->execute() or die("Problem saving profiles reload & tryagain!");
     

         #save user id data in the browser session
$sql = "SELECT userID FROM users WHERE userID='{$uID}'";
$result = $conn->query($sql);
session_regenerate_id();
if ($result->num_rows > 0) {
    while($uid = $result->fetch_assoc()) {
    
    $_SESSION["user_id"] = $uid["userID"];
    $uniq = uniqid("@user");
    $_SESSION["unique"] = $uniq;
    };
   echo "
   <div style='
   width: 100%;
    height: 700px;
    position: fixed;
    text-align: center;
    background-color: white;
    color: black;
    font-size: 30px;
    top: 0;
    left: 0;
    z-index: 7;
   '>
    Click the button to continue or reload this page to continue

   <br>
   <button style='
    width: 50%;
    height: 49px;
    position: fixed;
    background-color: #0000ff;
    color: white;
    font-size: 20px;
    background-image: linear-gradient(45deg, black, transparent);
    border-radius: 12px;
    left: 27%;
   ' onclick='letsgo()'>Click here</button>
   </div>
   
   
   
   ";
      }
  
$conn->close();