Show error message if that particular content is not in database - php

Question

Here I have code where user is going to be created, they have to enter one accesscode given by admin. That accesscode is limited by some users like 10 or 20. After that it shows error like your accesscode is limited. So until now, it's working fine.
Now if user tries to enter accesscode that is not given by admin it has to show error message like your accesscode is wrong.
Here is my code:
<?php
require('../config.php');
require_once($CFG->dirroot . '/user/editlib.php');
$errorMessage = '';
$successMessage = '';
if(isset($_SESSION['successMessage'])) {
$successMessage = $_SESSION['successMessage'];
unset($_SESSION['successMessage']);
}
if (isset($_POST['register'])) {
$errors = array();
$data = array();
$chk_sql = "SELECT * FROM {user} u where username = ?";
if (!empty($chk_sql) ) {
$errorMessage = 'Username already taken';
}
if(!$chk_username = $DB->get_record_sql($chk_sql, array($_POST['username']))) {
$secret = $_POST['secret'];
$access_code_sql = "SELECT * FROM {accesscode} WHERE random_no= ? and `number` > `used` and status=1";
if($chk_secret = $DB->get_record_sql($access_code_sql, array($secret))) {
$cadminid = $chk_secret->cadmin_id;
$clientid = $chk_secret->clientid;
$DB->execute("UPDATE {accesscode} SET used = used+1 WHERE random_no = '$secret'");
$insert_record = new stdClass();
$insert_record->firstname = $_POST['firstname'];
$insert_record->lastname = $_POST['lastname'];
$insert_record->username = $_POST['username'];
$insert_record->secret = $secret;
$insert_record->password = password_hash($_POST['password'], PASSWORD_DEFAULT);
$insert_record->timecreated = time();
$insert_record->maildigest = $cadminid;
$insert_record->maildisplay = $clientid;
$insert_record->idnumber = 1;
$insert_record->mnethostid = 1;
$insert_record->confirmed = 1;
$insert_record->email = $_POST['email'];
if ($result = $DB->insert_record('user', $insert_record)) {
$_SESSION['successMessage'] = "record created successfully";
header('Location: register.php');
} else
$errorMessage = "error! can you please try again";
} else
$errorMessage = "your access code limit completed";
}
}
?>

Answer 1

Can you give us more information about your problem? What doesn't work?Try some "var_dump()" in your loop to know if you pass through or not so you can tell us where is the problem !
But first thing I see is here :
if(! $chk_username = $DB->get_record_sql($chk_sql, array($_POST['username'])) )
and here :
if($result = $DB->insert_record('user', $insert_record))
You should use "==" or "===" because using "=" means you assign a value to "$chk_username" and "result".
Then here is some librairie you can use if you want to display flash message, this is just for your information :
https://github.com/plasticbrain/PhpFlashMessages
And if you want to do it in JS you can use : https://github.com/CodeSeven/toastr
Hope it helps !

Answer 2

i changed the condition like this
<?php
require('../config.php');
require_once($CFG->dirroot . '/user/editlib.php');
$errorMessage = '';
$successMessage = '';
if(isset($_SESSION['successMessage']))
{
$successMessage = $_SESSION['successMessage'];
unset($_SESSION['successMessage']);
}
if (isset($_POST['register'])) {
$errors = array();
$data = array();
$chk_sql = "SELECT * FROM {user} u where username = ?";
if (!empty($chk_sql) ) {
$errorMessage='Username already taken';
}
if(!$chk_username = $DB->get_record_sql($chk_sql, array($_POST['username']))
)
{
$secret = $_POST['secret'];
$access_code_sql = "SELECT * FROM {accesscode} WHERE random_no= ? and
status=1";
if($chk_secret = $DB->get_record_sql($access_code_sql, array($secret)) )
{
if ( $chk_secret->used >= $chk_secret->number ) {
$errorMessage = "your access code limit completed..";
}else
{
$cadminid = $chk_secret->cadmin_id;
$clientid = $chk_secret->clientid;
$DB->execute("UPDATE {accesscode} SET used = used+1 WHERE random_no = '$secret'");
$insert_record = new stdClass();
$insert_record->firstname = $_POST['firstname'];
$insert_record->lastname = $_POST['lastname'];
$insert_record->username = $_POST['username'];
$insert_record->secret = $secret;
$insert_record->password = password_hash($_POST['password'],
PASSWORD_DEFAULT);
$insert_record->timecreated = time();
$insert_record->maildigest = $cadminid;
$insert_record->maildisplay = $clientid;
$insert_record->idnumber = 1;
$insert_record->mnethostid = 1;
$insert_record->confirmed = 1;
$insert_record->email = $_POST['email'];
if($result = $DB->insert_record('user', $insert_record))
{
$_SESSION['successMessage'] = "record created successfully";
header('Location: register.php');
}
else
$errorMessage = "error! can you please try again";
}
}
else
$errorMessage = "your access code is wrong..";
}
}
?>
it's working..