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TOTD #111: Rails Scaffold for a pre-existing table using Oracle and GlassFish

TOTD #110 explained how to create a brand new Rails application using Oracle database and run it using GlassFish v Gem. This Tip Of The Day explains how to create a scaffold for a sample schema that ships with Oracle database. Even though Rails Scaffold are good for, well, scaffolding but they do get you started easily. This blog will use the sample HR schema that comes along with Oracle database.

Lets get started!

1. Copy the reverse_scaffold script in the "script" directory of your application created in TOTD #110. This script generates Model and Forms from a pre-existing database table. More details about this script are here.
2. Edit "config/database.yml" and change the "development" section to:
   
   development:
adapter: oracle_enhanced
host: localhost
database: orcl
username: hr
password: hr
   
   The changes are highlighted in bold, only the username and password values are changed to reflect the default values used with the sample database.
3. Generate the models and forms for "departments" table as:
   

   ~/samples/v3/rails/oracle/bookstore >~/tools/jruby/bin/jruby script/reverse_scaffold departments department
   JRuby limited openssl loaded. gem install jruby-openssl for full support.
   http://wiki.jruby.org/wiki/JRuby_Builtin_OpenSSL
   JRuby limited openssl loaded. gem install jruby-openssl for full support.
   http://wiki.jruby.org/wiki/JRuby_Builtin_OpenSSL
    exists app/models/
    exists app/controllers/
    exists app/helpers/
    create app/views/departments
    exists app/views/layouts/
    exists test/functional/
    exists test/unit/
    create test/unit/helpers/
    exists public/stylesheets/
    create app/views/departments/index.html.erb
    create app/views/departments/show.html.erb
    create app/views/departments/new.html.erb
    create app/views/departments/edit.html.erb
    create app/views/layouts/departments.html.erb
    create public/stylesheets/scaffold.css
    create app/controllers/departments_controller.rb
    create test/functional/departments_controller_test.rb
    create app/helpers/departments_helper.rb
    create test/unit/helpers/departments_helper_test.rb
    route map.resources :departments
    dependency model
    exists app/models/
    exists test/unit/
    exists test/fixtures/
    create app/models/department.rb
    create test/unit/department_test.rb
    create test/fixtures/departments.yml
   

4. Edit "app/models/department.rb" and specify the primary key to "department_id" column by adding:
   

   set_primary_key "department_id"
   

   
   
5. Run the application as:

   ~/samples/v3/rails/oracle/bookstore >~/tools/jruby/bin/jruby -S glassfish -l
   Starting GlassFish server at: 129.145.133.197:3000 in development environment...
   Writing log messages to: /Users/arungupta/samples/v3/rails/oracle/bookstore/log/development.log.
   Press Ctrl+C to stop.
   Oct 6, 2009 2:14:19 PM com.sun.enterprise.v3.services.impl.GrizzlyProxy start
   INFO: Listening on port 3000
   
   . . .
   

   
   The application is now accessible at "http://localhost:3000/departments" and looks like:
   
6. Similarly, create the model and forms for "employees" table as:
   
   

   ~/samples/v3/rails/oracle/bookstore >~/tools/jruby/bin/jruby script/reverse_scaffold employees employee
   JRuby limited openssl loaded. gem install jruby-openssl for full support.
   http://wiki.jruby.org/wiki/JRuby_Builtin_OpenSSL
   JRuby limited openssl loaded. gem install jruby-openssl for full support.
   http://wiki.jruby.org/wiki/JRuby_Builtin_OpenSSL
    exists app/models/
    exists app/controllers/
    exists app/helpers/
    create app/views/employees
    exists app/views/layouts/
    exists test/functional/
    exists test/unit/
    exists test/unit/helpers/
    exists public/stylesheets/
    create app/views/employees/index.html.erb
    create app/views/employees/show.html.erb
    create app/views/employees/new.html.erb
    create app/views/employees/edit.html.erb
    create app/views/layouts/employees.html.erb
    identical public/stylesheets/scaffold.css
    create app/controllers/employees_controller.rb
    create test/functional/employees_controller_test.rb
    create app/helpers/employees_helper.rb
    create test/unit/helpers/employees_helper_test.rb
    route map.resources :employees
    dependency model
    exists app/models/
    exists test/unit/
    exists test/fixtures/
    create app/models/employee.rb
    create test/unit/employee_test.rb
    create test/fixtures/employees.yml
   

   
   Specify the primary key to "employee_id" by adding the following to "app/models/employee.rb" as:
   

   set_primary_key "employee_id"
   

   
   The scaffolded table is now available at "http://localhost:3000/employees" and looks like:
   
   

So we created a simple Rails CRUD application accessing information from a pre-existing table in the Oracle database server.

Thanks to @mediachk for all the help!

A complete archive of all the TOTDs is available here. The complete list of Rails blog entries are available here.

This and other similar applications will be demonstrated at the upcoming Oracle Open World.

Technorati: totd oracle database glassfish v3 jruby rails oow

Posted by Arun Gupta in General  |  Comments[0]