ActiveRecord JDBC Adapter
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ActiveRecord-JDBC-Adapter (AR-JDBC) 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.
We do support ActiveRecord 3.x and 4.x (also 2.3 is still expected
to work) from a single code base. AR-JDBC needs JRuby 1.7.x or 9K (we recommend
using the latest and greatest of versions) thus Java >= 1.6 is mandatory.
This README and master targets AR-JDBC 1.4.0 (pre-release) please use the
1-3-stable
branch for current stable 1.3.x releases.
The next release 1.4 aims to concentrate on internal refactoring and optimization.
We're going to be (slowly) dropping support for all of Rails < 3.2, unless there
is demand for these. In which case we kindly hope to receive PRs.
Databases
ActiveRecord-JDBC-Adapter provides (built-in) full or nearly full support for:
MySQL (and MariaDB), PostgreSQL, SQLite3, Oracle, DB2,
MS-SQL* (SQL Server), Firebird, Derby, HSQLDB, H2, and Informix.
Even if you're database product is not listed, there are 3rd party gems built on
top of AR-JDBC to handle different data-sources, search at the usual places.
Using ActiveRecord JDBC
Inside Rails
To use AR-JDBC with JRuby on Rails:
- Choose the adapter (base is usually fine), the following are pre-packaged :
- Base JDBC (
activerecord-jdbc-adapter
) - supports all available databases
via JDBC (Java's unified DB interface), but requires you to setup a JDBC
driver (which with most open-source drivers means adding another gem to your
Gemfile e.g. gem 'jdbc-mysql'
just like on MRI), for drivers not packed
as gems just add the required jars to the class-path - MySQL (
activerecord-jdbcmysql-adapter
) - PostgreSQL (
activerecord-jdbcpostgresql-adapter
) - SQLite3 (
activerecord-jdbcsqlite3-adapter
) - Derby (
activerecord-jdbcderby-adapter
) - HSQLDB (
activerecord-jdbchsqldb-adapter
) - H2 (
activerecord-jdbch2-adapter
) - MSSQL (
activerecord-jdbcmssql-adapter
) - uses the OSS jTDS driver which
might have issues with the latest SQLServer (but should work using the
Microsoft JDBC Driver for SQL Server - we recommend using version 4.0)
NOTE: jTDS seems no longer maintained,
if you're run into issues consider using the official (proprietary) driver.
2a. If you're generating a new Rails application, run the usual :
jruby -S rails new sweetapp
2b. Otherwise, you might need to perform some extra configuration steps
to prepare your Rails application for JDBC.
You'll need to modify your Gemfile to use the activerecord-jdbc-adapter gem
(or one of the helper gems) under JRuby. Change your Gemfile to look something
like the following :
gem 'mysql2', platform: :ruby
gem 'jdbc-mysql', platform: :jruby
gem 'activerecord-jdbc-adapter', platform: :jruby
- Configure your database.yml in the normal Rails style :
development:
adapter: mysql2
database: blog_development
username: blog
password: 1234
Legacy Configuration: If you use one of the activerecord-jdbcxxx-adapter
gems, you can still put a 'jdbc' prefix in front of the database adapter name,
e.g. adapter: jdbcmysql
but it's no longer recommended on Rails >= 3.0
For plain JDBC database configurations, you'll need to know the database driver
class and URL (do not forget to put the driver .jar(s) on the class-path) e.g. :
development:
adapter: jdbc
driver: org.apache.hadoop.hive.jdbc.HiveDriver
url: jdbc:hive://localhost:10004/default
NOTE: please do not confuse the :url
setting with the one introduced in
ActiveRecord 4.1, we've been using it for a long time with AR-JDBC and for now
should work just fine the "jdbc:xxx" way (passed to the driver directly) ...
For JNDI data sources, you may simply specify the JNDI location as follows, it's
recommended to use the same adapter: setting as one would configure when using
"bare" (JDBC) connections e.g. :
production:
adapter: postgresql
jndi: jdbc/PostgreDS
NOTE: any other settings such as database:, username:, properties: make
no difference since everything is already configured on the data source end.
Most data-sources will provide you with connection pooling, but ActiveRecord uses
an internal pool (with a default size of 5) as well, thus you need to be careful
to configure both pools wisely to handle your requirements. If you'd like to
"disable" AR's built-in pool try : https://github.com/kares/activerecord-bogacs
JDBC driver specific properties might be set if you use an URL to specify the DB
or preferably using the properties: syntax :
production:
adapter: mysql
username: blog
password: blog
url: "jdbc:mysql://localhost:3306/blog?profileSQL=true"
properties:
socketTimeout: 60000
connectTimeout: 60000
If you're really old school you might want to use AR-JDBC with a DB2 on z/OS :
development:
adapter: db2
url: jdbc:db2j:net://mightyzoshost:446/RAILS_DBT1
schema: DB2XB12
database: RAILS_DB1
tablespace: TSDE911
lob_tablespaces:
first_table: TSDE912
username: business
password: machines
More information on (configuring) AR-JDBC might be found on our wiki.
Standalone with ActiveRecord
Once the setup is made (see below) you can establish a JDBC connection like this
(e.g. for activerecord-jdbcderby-adapter
):
ActiveRecord::Base.establish_connection adapter: 'derby', database: 'db/my-db'
Using Bundler
Proceed as with Rails; specify gem 'activerecord'
in your Bundle along with the
chosen JDBC adapter (or driver), sample Gemfile for MySQL :
gem 'activerecord', '~> 3.2.18'
gem 'activerecord-jdbcmysql-adapter'
When you require 'bundler/setup'
everything will be set up for you as expected.
You do not need to use the 'helper' activerecord-jdbcxxx-adapter gem we provide
but than should make sure an appropriate JDBC driver is available at runtime, in
that case simply setup your Gemfile as:
gem 'activerecord', '~> 4.1.6'
gem 'activerecord-jdbc-adapter', '~> 1.3', platform: :jruby
Without Bundler
Install the needed gems with JRuby, for example:
gem install activerecord -v "~> 3.2"
gem install activerecord-jdbc-adapter --ignore-dependencies
If you wish to use the adapter for a specific database, you can install it
directly and the (jdbc-) driver gem (dependency) will be installed as well:
jruby -S gem install activerecord-jdbcderby-adapter
Your program should include:
require 'active_record'
require 'activerecord-jdbc-adapter' if defined? JRUBY_VERSION
require 'activerecord-jdbcderby-adapter' if defined? JRUBY_VERSION
Extending AR-JDBC
You can create your own extension to AR-JDBC for a JDBC-based database that core
AR-JDBC does not support. We've created an example project for the Intersystems
Cache database that you can examine as a template.
See the cachedb-adapter project for more information.
Source
The source for activerecord-jdbc-adapter is available using git:
git clone git://github.com/jruby/activerecord-jdbc-adapter.git
You will need to have JDK 7+ to compile the native JRuby extension part.
NOTE: Currently, one also needs to make sure to install all of the gem's
development dependencies to make sure the compilation javac
task does
found it's dependent (Java) classes.
Please note that the project manages multiple gems from a single repository,
if you're using Bundler >= 1.2 it should be able to locate all gemspecs from
the git repository. Sample Gemfile for running with (MySQL) master:
gem 'activerecord-jdbc-adapter', :github => 'jruby/activerecord-jdbc-adapter'
Getting Involved
Please read our CONTRIBUTING & RUNNING_TESTS
guides for starters. You can always help us by maintaining AR-JDBC's wiki.
Feedback
Please report bugs at our issue tracker. If you're not sure if something's
a bug, feel free to pre-report it on the mailing lists or ask on the #JRuby
IRC channel on http://freenode.net/ (try web-chat).
Authors
This project was originally written by Nick Sieger
and Ola Bini with lots of help from the community.
Polished 3.x compatibility and 4.x support (since AR-JDBC >= 1.3.0) was managed by
Karol Bucek among other fellow JRuby-ists.
License
ActiveRecord-JDBC-Adapter is open-source released under the BSD/MIT license.
See LICENSE.txt included with the distribution for details.
Open-source driver gems within AR-JDBC's sources are licensed under the same
license the database's drivers are licensed. See each driver gem's LICENSE.txt.