Active Record Database Adapters

ActiveRecord comes with built-in support for SQLite, PostgreSQL and MySQL on the offical C-based Ruby implementation commonly referred to as "MRI". These extensions let you connect to other relational databases or use other Ruby implementations like JRuby.

A long-lived project that still receives updates
AR-JDBC is a database adapter for Rails' ActiveRecord component designed to be used with JRuby built upon Java's JDBC API for database access. Provides (ActiveRecord) built-in adapters: MySQL, PostgreSQL and SQLite3 as well as adapters for popular databases such as Oracle, SQLServer, DB2, FireBird and even Java (embed) databases: Derby, HSQLDB and H2. It allows to connect to virtually any JDBC-compliant database with your JRuby on Rails application.
No release in over a year
A database backend that translates database interactions into no-ops. Using NullDB enables you to test your model business logic - including after_save hooks - without ever touching a real database.
No commit activity in last 3 years
No release in over 3 years
This gem includes several enhancements and customizations to the standard ActiveRecord Oracle Enhanced adapter, which is still required. Any customizations to this adapter's behaviour or additional Oracle-specific utilities should be added here.