Rails efficient way to save non-duplicates?

I ha开发者_JAVA技巧ve a type I want to save to the database, say, email addresses, and I want to save them in the most efficient way possible. I also want to associate posts with email addresses, so if it exists, I want to assign the post to that email address. Should I do a search first and then go based on that result, or is there a more efficient way? for ex, if it doesn't exist, I just want it to insert, I don't want to then to have to insert it after a search; that takes 2 calls where 1 would do.

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I believe you should use something like find_or_create.

Does post and email are separated models and post has_one email?

Edit

When creating a post, you should do something like

# posts controller
@email = Email.find_or_initialize_by_address(params[:email])
@post.email = @email #or whatever you do to associate them