Rails 3 自定义验证 Email 唯一性

Question

I am using Riak database for my current project which does not support the "uniqueness" helper method. Now I want to validate user email for uniqueness. How to write the custom validation for unique emial address??

Answer 1

Try something like this. You may have to modify the User.exists? part if that doesn't work with your DB.

class User
  validate :verify_unique_email

  def verify_unique_email
    if User.exists? email: email
      errors.add :email, 'has already been taken'
    end
  end
end

Answer 2

You could put something like this in your validator:

Class User
  validate :unique_email_address?

  def unique_email_address?
    return false if User.where(email: self.email).any?
  end

end

Let me know if you need help with the custom validator file.

Answer 3

This worked for me in Rails 7.

class User
  validate :verify_unique_email

  def verify_unique_email
    if !User.find_by(email: email).nil?
      errors.add :email, 'has already been taken'
      throw :abort
    end
  end
end