varchar Migration question for Ruby on Rails

The correct format would be

t.string :note, :limit => 1000

make sure you are using a version of MySQL(or whichever database) which supports varchars longer than 256 characters.

if you want to use a large text block it would be

t.text :note

See http://api.rubyonrails.org/classes/ActiveRecord/ConnectionAdapters/TableDefinition.html for more information