ActiveRecord adapter for JDBC and JRuby. Alternate clone at git://

activerecord-jdbc-adapter is a database adapter for Rails’ ActiveRecord component that can be used with JRuby[]. It allows use of virtually any JDBC-compliant database with your JRuby on Rails application.

== Project Info

== Databases

What’s there, and what is not there:

  • MySQL - Complete support
  • PostgreSQL - Complete support
  • Oracle - Complete support
  • Microsoft SQL Server - Complete support except for change_column_default
  • DB2 - Complete, except for the migrations:
    • change_column
    • change_column_default
    • remove_column
    • rename_column
    • add_index
    • remove_index
    • rename_table
  • FireBird - Complete, except for change_column_default and rename_column
  • Derby - Complete, except for:
    • change_column
    • change_column_default
    • remove_column
    • rename_column
  • HSQLDB - Complete
  • H2 - Complete
  • SQLite3 - work in progress
  • Informix - Fairly complete support, all tests pass and migrations appear to work. Comments welcome.

Other databases will require testing and likely a custom configuration module. Please join the activerecord-jdbc mailing-lists[] to help us discover support for more databases.

== Using ActiveRecord JDBC

=== Inside Rails

To use activerecord-jdbc-adapter with JRuby on Rails:

  1. Choose the adapter you wish to gem install. The following pre-packaged adapters are available:

    • base jdbc (activerecord-jdbc-adapter). Supports all available databases via JDBC, but requires you to download and manually install the database vendor’s JDBC driver .jar file.
    • mysql (activerecord-jdbcmysql-adapter)
    • postgresql (activerecord-jdbcpostgresql-adapter)
    • derby (activerecord-jdbcderby-adapter)
    • hsqldb (activerecord-jdbchsqldb-adapter)
    • h2 (activerecord-jdbch2-adapter)
    • sqlite3 (activerecord-jdbcsqlite3-adapter)
  2. Run the “jdbc” generator to prepare your Rails application for JDBC.

    jruby script/generate jdbc

The initializer and rake task files generated are guarded such that they won’t be loaded if you still run your application un C Ruby.

Legacy: If you’re using Rails prior to version 2.0, you’ll need to add one-time setup to your config/environment.rb file in your Rails application. Add the following lines just before the Rails::Initializer. (If you’re using activerecord-jdbc-adapter under the old gem name used in versions 0.5 and earlier (ActiveRecord-JDBC), replace ‘activerecord-jdbc-adapter’ with ‘ActiveRecord-JDBC’ below.)

if RUBY_PLATFORM =~ /java/
  require 'rubygems'
  gem 'activerecord-jdbc-adapter'
  require 'jdbc_adapter'
  1. Configure your database.yml in the normal Rails style.

Legacy configuration: If you use one of the convenience ‘activerecord-jdbcXXX-adapter’ adapters, you can still put a ‘jdbc’ prefix in front of the databas adapter name as below.

  adapter: jdbcmysql
  username: blog
  hostname: localhost
  database: weblog_development

For other databases, you’ll need to know the database driver class and URL. Example:

  adapter: jdbc
  username: blog
  driver: com.mysql.jdbc.Driver
  url: jdbc:mysql://localhost:3306/weblog_development

=== Standalone, with ActiveRecord

  1. Install the gem with JRuby:

    jruby -S gem install activerecord-jdbc-adapter

If you wish to use the adapter for a specific database, you can install it directly and a driver gem will be installed as well:

jruby -S gem install activerecord-jdbcderby-adapter
  1. If using ActiveRecord 2.0 (Rails 2.0) or greater, you can skip to the next step. Otherwise, ensure the following code gets executed in your script:

    require ‘rubygems’ gem ‘activerecord-jdbc-adapter’ require ‘jdbc_adapter’ require ‘active_record’

  2. After this you can establish a JDBC connection like this:

    ActiveRecord::Base.establish_connection( :adapter => ‘jdbcderby’, :database => “db/my-database” )

or like this (but requires that you manually put the driver jar on the classpath):

  :adapter => 'jdbc',
  :driver => 'org.apache.derby.jdbc.EmbeddedDriver',
  :url => 'jdbc:derby:test_ar;create=true'

== Getting the source

The source for activerecord-jdbc-adapter is available using git.

git clone git://

== Feedback

Please file bug reports at If you’re not sure if something’s a bug, feel free to pre-report it on the mailing lists.

== Running AR-JDBC’s Tests

Drivers for 6 open-source databases are included. Provided you have MySQL installed, you can simply type jruby -S rake to run the tests. A database named weblog_development is needed beforehand with a connection user of “blog” and an empty password.

If you also have PostgreSQL available, those tests will be run if the `psql’ executable can be found. Also ensure you have a database named weblog_development and a user named “blog” and an empty password.

If you want rails logging enabled during these test runs you can edit test/jdbc_common.rb and add the following line:

require ‘db/logger’

== Running AR Tests

To run the current AR-JDBC sources with ActiveRecord, just use the included “rails:test” task. Be sure to specify a driver and a path to the ActiveRecord sources.

jruby -S rake rails:test DRIVER=mysql RAILS=/path/activerecord_source_dir

== Authors

This project was written by Nick Sieger [email protected] and Ola Bini [email protected] with lots of help from the JRuby community.

== License

activerecord-jdbc-adapter is released under a BSD license. See the LICENSE file included with the distribution for details.

Open-source driver gems for activerecord-jdbc-adapter are licensed under the same license the database’s drivers are licensed. See each driver gem’s LICENSE.txt file for details.

Related Repositories



ActiveRecord adapter using JDBC for JRuby. Please, support the project at BountySource's ...



ActiveRecord JDBC Adapter for Teradata ...



ActiveRecord adapter for JDBC and JRuby<br>Alternate clone at git:// ...



ActiveRecord adapter for JDBC and JRuby<br>Alternate clone at git:// ...



ActiveRecord adapter for JDBC and JRuby. ...

Top Contributors

nicksieger kofno ryanfb saturnflyer nchaugen ivern edsono adkron dekellum enebo bbrowning dpowell dudleyf lackac marcelomurad Lamar


-   v0.9.1 zip tar
-   v0.9 zip tar
-   v0.8.2 zip tar
-   v0.8.1 zip tar