Open a database require 'rubygems' require 'sequel' DB = Sequel.sqlite 'my_blog.db' DB = Sequel.connect('postgres://user:password@localhost/my_db') DB = Sequel.mysql 'my_db', :user => 'user', :password => 'password', :host => 'localhost' DB = Sequel.ado 'mydb' Open an SQLite memory database Without a filename argument, the sqlite adapter will setup a new sqlite database in RAM. DB = Sequel.sqlite