check if username is not taken between two tables - php

Question

Well i have a problem. I have a registration for for legal users and natural users, but i need to write a validation in each php file for username checking, i have no idea how to combine two table checking.
one table is called users_legal, 2nd one is users_natural. In both forms name for input field is "username".
So far i have a code that checks passwords :
if ($password == $password_re)
{
// insert into table
$sql = $db->prepare("INSERT INTO users_legal(name, reg_number, address, phone, email, username, password) VALUES(?, ?, ?, ?, ?, ?, ?);");
$sql->bind_param("sssssss", $name, $reg_number, $address, $phone, $email, $username, $password);
$sql->execute();
$sql->close();
}
After makeing a validation in register forms, i also need it in login page. I figured out how to check if there is only and only one user with that username and that password, but i have no idea how to search them between tables.
login.php code :
if($_SERVER["REQUEST_METHOD"] == "POST") {
// username and password sent from form
$myusername = mysqli_real_escape_string($db,$_POST['username']);
$mypassword = mysqli_real_escape_string($db,$_POST['password']);
$sql = "SELECT id FROM login WHERE username = '$myusername' and password = '$mypassword'";
$result = mysqli_query($db,$sql);
$row = mysqli_fetch_array($result,MYSQLI_ASSOC);
$active = $row['active'];
$_SESSION['username'] = $myusername;
$count = mysqli_num_rows($result);
if($count == 1) {
session_register("myusername");
$_SESSION['username'] = $myusername;
$_SESSION['loggedin'] = true;
header("location: www.goole.lv");
}else {
$error = "Your Login Name or Password is invalid";
}
}
One more thing : i set my mysql to utf format, var_dump says that input is allright, but in mysql it saves in unbelievuble forms, like Ķegums or Skrīvelis.
Thnx for any examples, tips or whateva u got.

Answer 1

When I got you right, you have two tables with users. To validate if an user has logged in successfully you look up their login credentials in the related database table.
You are asking for 'combining' these two tables. But I don't think that that's what you want. You have two separate user tables. They do not belong to each other. If you join those tables, you might have dulicate unique user ids when combining these tables.
What you could do instead is check both tables separately, first for users_legal and second for users_natural.
You should also think about using password hashes instead of plain passwords in your db. And use pdo ;)
Good luck

Answer 2

To solve the problem of having two different types of users I would just put them in the same table and add a value that represents the user type for example 0 = legal and 1 = natural. This will also automatically prevent two users from sharing the same username. (This will only work for sure if the database is still empty, if not you might end up with two users with the same name). For the character encoding try setting mysql to utf-8 if you haven’t done it already (instead of just utf). Also you should never save passwords in plaintext. Use the sha1 function in php to convert them to their hash value before storing them. That way even if someone gets unauthorized access to the database they still won’t know the passwords. You should also append some user specific information to the password before hashing so that even if two users share the same password their hash values will be different. To verify if it’s correct you just apply the same procedure to the input before comparing it with the hash value you have stored.