Trying to reproduce https://github.com/rails/rails/issues/15900

gistfile1.rb

ActiveRecord::Base.establish_connection(
  :adapter => 'sqlite3',
  :database => 'testing.db'
)

class Testing < ActiveRecord::Base

end

Testing.connection.create_table :testings do |t|
  t.string :format
end

record = Testing.new(format: 'foo')
record.save!

record = Testing.first
record.send('format')