Sequel is a database toolkit for the Ruby programming language that provides abstractions over many SQL RDBMS.
Sequel is a "Database Toolkit for Ruby" that:
...provides thread safety, connection pooling and a concise DSL for constructing SQL queries and table schemas.
...includes a comprehensive ORM layer for mapping records to Ruby objects and handling associated records.
...supports advanced database features such as prepared statements, bound variables, stored procedures, savepoints, two-phase commit, transaction isolation, master/slave configurations, and database sharding.
...has adapters for ADO, Amalgalite, DataObjects, DB2, DBI, Firebird, Informix, JDBC, MySQL, Mysql2, ODBC, OpenBase, Oracle, PostgreSQL, SQLite3, and Swift.
See the documentation for a list of guides, examples, tutorials, and other reference material.
Sequel is currently maintained and primarily developed by Jeremy Evans.