I had to think about the database design of ProcessWire (PHP CMS). It uses one table for identifiers and field tables for all data connected to the identifier.

I had to think about the database design of ProcessWire (PHP CMS). It uses one table for identifiers and field tables for all data connected to the identifier. To store a user with a username, a password and an email address it uses 3 tables. One for the username (identifier), one for the password and one for the email address. The only safe way to insert a user is by using transactions.