adding user info and log in info in different page - php

Question

so I want to make a sign up where at the first page, is the user info where the name, last name etc will be input by the user, then it will be recorded into the database and redirect to the account info page where the user input the username and password and be recorded in another database so I have to tables the student, where all the info is stored, and user, where account info is stored so the userID of the user will be the foreign key of in the student but I cant put the id number of the user to the table of the student where the first input is stored in the first page, so if I use the mysqli_insert_id it can insert the id of the last inserted user into the student table but into the next row not the row where the last input of information in the first page is located
code in the first page shs/functions/add.stud.php
<?php
session_start();
include 'database.php';
if (isset($_POST['add'])) {
echo "welcome";
}
$message = "Provide all information needed please";
$lname = $_POST['Lname'];
$fname = $_POST['Fname'];
$mname = $_POST['Mname'];
$email = $_POST['email'];
$grade = $_POST['grade'];
$strand = $_POST['strand'];
$section = $_POST['section'];
$status = $_POST['status'];
if (empty($lname) || empty($mname)) {
header("Location:../pages/user.add.php?empty=put something, will ya?");
exit();
}
else {
$sql = "INSERT INTO student (lname, fname, mname, gmail, grade, track, section, status)
VALUES ('$lname', '$fname', '$mname','$email', '$grade', '$strand', '$section', '$status')";
$result = mysqli_query($conn, $sql);
}
then in the account information (username, password)
<?php
if (isset($_POST['users'])){
include_once 'database.php';
$uid = $_POST['uid'];
$pass = $_POST['pass'];
//pag check or pag handle sa mga errors sa pag log in
if (empty($uid) || empty($pass))
{
header("location:../pages/user.add.php?signup=empty fields");
exit();
} else {
$sql = "SELECT * FROM 'user' WHERE username ='$uid'";
$result = mysqli_query($conn, $sql);
$resultCheck = mysqli_num_rows($result);
if ($resultCheck < 0) {
header("Location:.../user.add.php?the inputs are already taken");
exit();
}
else {
$hashedpass = password_hash($pass, PASSWORD_DEFAULT);
//insert the new user to the user database
$sql = "INSERT INTO user (userID, username, password)
VALUES (NULL, '$uid', '$hashedpass');";
$result = mysqli_query($conn, $sql);
//pag connect sa student database
//katung sa database sa image
$sql = "SELECT * FROM user WHERE username ='$uid'";
$result = mysqli_query($conn, $sql);
if (mysqli_num_rows($result) > 0){
while ($row = mysqli_fetch_assoc($result)){
$userid = $row['userID'];
$sql = "INSERT INTO profileimg (userID, status)
VALUES ('$userid', 1)";
if($result=mysqli_query($conn, $sql))
{
$last_id = mysqli_insert_id($conn);
$sql = "INSERT INTO student (userID) VALUES ('$last_id')";
$result = mysqli_query($conn, $sql);
}
else {
header("Location:.../user.add.php");
exit();
}
//pag add sa id sa user paingun sa student
header("Location:../pages/user.add.php");
}
}
after putting the inputs in the first page it will redirect to another page where the user must input the account info..that's the desired function

Answer 1

The best way is to store the User Info in the student table then use the mysqli_insert_id function to grab the studentId. Then save the Account Info in the user table and grab the userId. Thereafter update the student table with userId where studentId is the same as the one you grabbed earlier.
$sql = "INSERT INTO student (lname, fname, mname, gmail, grade, track, section, status)
VALUES ('$lname', '$fname', '$mname','$email', '$grade', '$strand', '$section', '$status')";
$result = mysqli_query($conn, $sql);
$_SESSION['studentId'] = mysqli_insert_id($conn); //add this line to store the studentId into the session.
$sql = "INSERT INTO student (userID) VALUES ('$last_id')"; // change this line to the one below.
$sql = "UPDATE student SET userID = '$last_id' WHERE studentID = $_SESSION['studentId']";