Free and open source database access toolkit for Ruby
Sequel makes it easy to deal with multiple records without having to break your teeth on SQL.
Sequel is designed to take the hassle away from connecting to databases and manipulating them. Sequel deals with all the boring stuff like maintaining connections, formatting SQL correctly and fetching records so you can concentrate on your application.
Sequel uses the concept of datasets to retrieve data. A Dataset object encapsulates an SQL query and supports chainability, letting you fetch data using a convenient Ruby DSL that is both concise and infinitely flexible.
Sequel currently supports: ADO (on Windows), ODBC, Oracle, PostgreSQL, DBI, Informix, MySQL, SQLite 3.There are also experimental adapters for DB2, OpenBase and JDBC (on JRuby).
NOTE: Sequel is licensed and distributed under the MIT/X Consortium License.