Take id from one table and insert in another same time - php

Question

I want to insert in the security the same id from users:
<?php
if (isset($_POST['reg_user'])) {
require 'db.php';
$username = $_POST['username'];
$email = $_POST['email'];
$password = $_POST['password_1'];
$passwordRepeat = $_POST['password_2'];
$firstName = $_POST['firstname'];
$lastName = $_POST['lastname'];
$country = $_POST['country'];
$city = $_POST['city'];
$address = $_POST['address'];
$zipCode = $_POST['zipCode'];
if (empty($username) || empty($email) || empty($password) || empty($passwordRepeat) || empty($firstName) || empty($lastName) || empty($country) || empty($city) || empty($address) || empty($zipCode)) {
header("Location: ../sign_up.php?error=emptyfields&uid=" . $username . "&mail=" . $email);
exit();
} elseif (strlen($username) < 3) {
header("Location: ../sign_up.php?error=short_username=" . $username . "");
exit();
} elseif (strlen($username) > 17) {
header("Location: ../sign_up.php?error=long_username=" . $username . "");
exit();
} elseif (!filter_var($email, FILTER_VALIDATE_EMAIL) && !preg_match("/^[a-zA-Z0-9]*$/", $username)) {
header("Location: ../sign_up.php?error=invalidmailuid");
exit();
} elseif (!filter_var($email, FILTER_VALIDATE_EMAIL)) {
header("Location: ../sign_up.php?error=invalidmail&uid=" . $username);
exit();
} elseif (!preg_match("/^[a-zA-Z0-9]*$/", $username)) {
header("Location: ../sign_up.php?error=invaliduid&mail=" . $email);
exit();
} elseif ($password !== $passwordRepeat) {
header("Location: ../sign_up.php?error=passwordcheck&uid=" . $username . "&mail=" . $email);
exit();
} else {
$sql = "SELECT username FROM users WHERE username=?";
$stmt = mysqli_stmt_init($conn);
if (!mysqli_stmt_prepare($stmt, $sql)) {
header("Location: ../sign_up.php?error=sqlerror");
exit();
} else {
mysqli_stmt_bind_param($stmt, "s", $username);
mysqli_stmt_execute($stmt);
mysqli_stmt_store_result($stmt);
$resultCheck = mysqli_stmt_num_rows($stmt);
if ($resultCheck > 0) {
header("Location: ../sign_up.php?error=usertaken&mail=" . $email);
exit();
} else {
$sql = "INSERT INTO users (username, email, password) VALUES (?, ?, ?)";
$stmt = mysqli_stmt_init($conn);
if (!mysqli_stmt_prepare($stmt, $sql)) {
header("Location: ../sign_up.php?error=sqlerror");
exit();
} else {
$hashedPwd = password_hash($password, PASSWORD_DEFAULT);
mysqli_stmt_bind_param($stmt, "sss", $username, $email, $hashedPwd);
mysqli_stmt_execute($stmt);
$sql = "INSERT INTO security (username, firstName, lastName, country, city, address, zipcode) VALUES (?, ?, ?, ?, ?, ?, ?)";
$stmt = mysqli_stmt_init($conn);
mysqli_stmt_prepare($stmt, $sql);
mysqli_stmt_bind_param($stmt, "sssssss", $username, $firstName, $lastName, $country, $city, $address, $zipCode);
mysqli_stmt_execute($stmt);
header("Location: ../sign_up.php?signup=succes");
exit();
}
}
}
}
mysqli_stmt_close($stmt);
mysqli_close($conn);
} else {
header("Location: ../sign_up.php");
exit();
}
Replace username from security with id from "users" table, but I don't know the id from this user because it executes at the same time, any solutions?
P.S: ID, auto increment primary key
I want to know that security data is from that user (id).

Answer 1

You can get the last inserted id in mysqli using
$conn->insert_id;
Right after executing the insertion of the item. ($conn being the instance of the msqli class)