ben.rb

def self.import(file)
  CSV.foreach(file.path, headers: true) do |row|
    house = find_or_initialize_by(id: row['business_id']) # needed to specify what column to use when finding it
    # Explicit mappings is important for maintainability and so it's clear what columns you expect.
    house.attributes = {
      address: row['address'],
      whatever: row['what_ever'],
      blah: row['blah_column']
    }
    # this overwrites all data of any pre-existing records, too, which is probably a bad idea
    # what if the spreadsheet contains 3 rows with the same business_id by mistake?
    # Now you've just destroyed at least 2 pre-existing records. Better would be to
    # find_or_initialize_by the id plus one other attribute that will always be the same for the given id
    house.save!
  end
end

matt.rb

 def self.import(file)
    CSV.foreach(file.path, headers: true) do |row|
      vacation_home = find_or_initialize_by(:row['business_id']) || new
      vacation_home.attributes = row.to_hash
      vacation_home.save!
    end
  end