<?php
	$db = new SQLite3('mysqlitedb.db');
	$userPattern = '/[a-zA-Z0-9]{3,}/';
	$user = $_POST['username'];
	$pass = $_POST['userpassword'];
	$mail = $_POST['email'];

	if(preg_match($userPattern, $_POST['username'])){
		$db->query('INSERT INTO users ("'.$user.'", "'.$pass.'", "'.$mail.'");');
		echo "udao sie";
	} else {
		echo "Niepoprawny format loginu";
	}

?>

<div>
	<form  method="POST" >

		<input type="text" name="username" placeholder="Login" required value="" /><br />
		<input type="password" name="userpassword" placeholder="Hasło" required value="" /><br />
		<input type="text" name="email" placeholder="Adres e-mail" required value="" /><br />
		<input type="submit" value="Rejestruj" /><br />

	</form>
</div>