How do I authenticate a user in PHP / MySQL?

Question

So recently I learned how to properly add a username and password to a database. My database is usersys, and the table storing user information is called userdb. The table h

Answer 1

You can use sessions. Sessions are global variables that when set, stay with the user while he is browsing through the site.

Since you are learning PHP, try out this tutorial on the official website.

But what you would do in theory is when the username and password match, you set a session variable

$_SESSION["auth"] = true;
$_SESSION["user_id"] = $row["user_id"];

And then do a check to see if the user is authenticated.