ActiveRecord JDBC

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.

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 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)

2. If you're using Rails 2.0, you may skip to the next step. For 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'
    end

3. Configure your database.yml to use the jdbc adapter. For mysql, postgres, derby, oracle, hsqldb, h2, and informix you can simply configure the database in the normal Rails style. If you use one of the convenience 'activerecord-jdbcXXX-adapter' adapters, be sure and put a 'jdbc' prefix in front of the databas adapter name as below.

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

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

    development:
      adapter: jdbc
      username: blog
      password:
      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

2. 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'

3. 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):

    ActiveRecord::Base.establish_connection(
      :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://github.com/nicksieger/activerecord-jdbc-adapter.git

Running AR-JDBC's Tests

Drivers for 4 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 password empty.

Authors

This project was written by Nick Sieger <nick@nicksieger.com> and Ola Bini <olabini@gmail.com> 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.