Note to Myself

This morning I couldn’t remember how to get an array with only the unique properties of a Model attribute. For instance, I have a User model, and I want to retrieve the list of all my users' cities. I also don’t want to retrieve all the attributes and only the unique rows.

in my model:

<code>def self.cities
    User.find(:all, :select => "DISTINCT city").map(&:city)
end
</code>

Clean and simple, but for some reason I know I’ll forget and loose 5 minutes trying different things.