Or should I have username, email, password and set save username also as email?
edit: I am not using email as the pk but am using a unique index on the email
I feel like if I decided to change to openid/usernames I can still do that in the future by adding another column
I’d do email/password. And if you ever want to add usernames you can upgrade it then. No need to use extra fields if they’re the same and you don’t need them.