I'm using PDO connection to the database. I have 2 tables in the database one is users and the second is profile. The table users has one row: a specific user that I have set when I made the table and it won't change and the table profile has two columns: firstname and last name and the 2 tables are connected with a foreign key: user_id which is the Primary key of the first table (users). I have a form that a user types the input and it's stored...