$ irb
irb(main):001:0> #!/usr/bin/ruby
irb(main):002:0*
irb(main):003:0* require 'rubygems'
=> true
irb(main):004:0> require 'sequel'
=> true
irb(main):005:0>
irb(main):006:0* DB = Sequel.connect("sqlite://foo.db")
=> #<Sequel::SQLite::Database: "sqlite:/foo.db">
irb(main):007:0>
irb(main):008:0* class User < Sequel::Model
irb(main):009:1>   set_schema do
irb(main):010:2*     primary_key :id
irb(main):011:2>
irb(main):012:2*     varchar :username
irb(main):013:2>     varchar :password
irb(main):014:2>     timestamp :created
irb(main):015:2>   end
irb(main):016:1>
irb(main):017:1* end
=> :id
irb(main):018:0> User.create_table! unless User.table_exists?
=> [:id, :username, :password, :created]
irb(main):019:0>
irb(main):020:0* if User.empty?
irb(main):021:1>   User.create(:username => 'h4z3', :password => 'abc', :created => Time.now)
irb(main):022:1> end
=> #<User @values={:password=>"abc", :created=>Wed Apr 01 15:32:40 -0700 2009, :id=>1, :username=>"h4z3"}>
irb(main):023:0> p User.all
[#<User @values={:password=>"abc", :created=>Wed Apr 01 15:32:40 -0700 2009, :id=>1, :username=>"h4z3"}>]
=> nil
irb(main):024:0> $ ls
CHANGELOG   COPYING     README.rdoc Rakefile    bin         doc         extra       foo.db      lib         pkg         spec        www
$ sqlite3 foo.db
SQLite version 3.6.4
Enter ".help" for instructions
Enter SQL statements terminated with a ";"
sqlite> .dump
BEGIN TRANSACTION;
CREATE TABLE `users` (`id` integer PRIMARY KEY AUTOINCREMENT, `username` varchar(255), `password` varchar(255), `created` timestamp);
INSERT INTO "users" VALUES(1,'h4z3','abc','2009-04-01T15:32:40-07:00');
DELETE FROM sqlite_sequence;
INSERT INTO "sqlite_sequence" VALUES('users',1);
COMMIT;