sequel_jdbc_issue.rb

#!/usr/bin/env ruby

require 'rubygems'
require 'sequel'

DB = Sequel.connect('jdbc:sqlite:memory:')

DB.create_table :items do
  primary_key :id
  String  :string_attribute
  Boolean :boolean_attribute
end

DB[:items].insert(string_attribute:  'Foo',
                  boolean_attribute: false)

item = DB[:items].first

puts item[:boolean_attribute].class
puts item[:boolean_attribute].inspect

# => String
# => "f"
#
# with JRuby 1.7.2

According to this spec of sequel, sequel's jdbc adapter for sqlite3 does not support generic boolean type.