Using Ruby on Railswith legacy Oracle databases

Raimonds Simanovskis

Ruby => Oracle

Ruby application

ruby-oci8

require 'oci8'OCI8.new('scott', 'tiger').exec('select * from emp') do |r| puts r.join(',')end

Oracle Instant Client Oracle Database

SQL*Net

JRuby => Oracle

Ruby application

JRuby

require "java"sql = JavaSQL::DriverManager.getConnection(db, user, password)statement = sql.createStatementstatus = statement.execute "select * from parts;"rs = statement.getResultSet()

JDBC driver Oracle Database

SQL*Net

ActiveRecordOracle Enhanced

Adapter

Ruby on Rails 2.x => Oracle

gem install activerecord-oracle_enhanced-adapter

database.ymldevelopment: adapter: oracle_enhanced database: XE username: blogdemo password: blogdemo encoding: utf8

SQL bind variables

database.ymldevelopment: adapter: oracle_enhanced database: XE username: blogdemo password: blogdemo encoding: utf8 cursor_sharing: similar

Employee.find(1)

SELECT * FROM employees WHERE (employees.id = 1)

SELECT * FROM employees WHERE (employees.id = :SYS_B_0)

ActiveRecord

Oracle optimizer

Oracle Data TypesRuby Rails Oracle

Fixnum :integer NUMBERFloat :float NUMBER

BigDecimal :decimal NUMBER, DECIMALTime :datetime DATETime :time DATEDate :date DATEString :string VARCHAR2String :text CLOB

True/FalseClass :boolean NUMBER(1), CHAR(1)

WorkaroundsActiveRecord::ConnectionAdapters::OracleEnhancedAdapter. emulate_dates_by_column_name = truehire_date # Oracle DATE => Ruby Datehire_time # Oracle DATE => Ruby Time

set_date_columns :started_on, :finished_onset_datetime_columns :start_date_and_time, :end_date_and_time

ActiveRecord::ConnectionAdapters::OracleEnhancedAdapter. emulate_booleans_from_strings = trueactive_flag # Oracle CHAR(1) ‘Y’/’N’ => true/false

set_boolean_columns :some_boolean_column

ignore_table_columns :attribute1, :attribute2

Calling PL/SQL from Rubyrequire "oci8"conn = OCI8.new("hr","hr","xe")

cursor = conn.parse <<-EOSBEGIN :return := test_uppercase(:p_string);END;EOScursor.bind_param(':p_string',"xxx",String)cursor.bind_param(':return',nil,String,4000)cursor.execputs cursor[':return']cursor.close

ruby-plsql gem

gem install ruby-plsql

require "ruby-plsql"plsql.connection = OCI8.new("hr","hr","xe")

puts plsql.test_uppercase('xxx')

ruby-plsql gemplsql.connection = OCI8.new("hr","hr","xe")

plsql.test_uppercase('xxx') # => "XXX"plsql.test_uppercase(:p_string => 'xxx') # => "XXX"plsql.test_copy("abc", nil, nil) # => { :p_to => "abc", # :p_to_double => "abcabc" }plsql.test_copy(:p_from => "abc", :p_to => nil, :p_to_double => nil) # => { :p_to => "abc", # :p_to_double => "abcabc" }plsql.hr.test_uppercase('xxx') # => "XXX"plsql.test_package.test_uppercase('xxx') # => 'XXX'plsql.hr.test_package.test_uppercase('xxx') # => 'XXX'

plsql.logoff

Custom CUD

methods

class Employee < ActiveRecord::Base set_create_method do plsql.employees_pkg.create_employee( :p_first_name => first_name, :p_last_name => last_name, :p_employee_id => nil )[:p_employee_id] end set_update_method do plsql.employees_pkg.update_employee( :p_employee_id => id, :p_first_name => first_name, :p_last_name => last_name ) end set_delete_method do plsql.employees_pkg.delete_employee( :p_employee_id => id ) endend

Other features

• composite_primary_keys support

• NLS_DATE_FORMAT independent

• TIMESTAMP columns support

• Faster schema dump

DEMO

see code athttp://github.com/rsim/legacy_oracle_sample

Ruby on Rails on Oracle

EBS

Ruby on Rails application

Oracle E-Business Suite database

APPS schema XXX schema

XXX tablescustom views

for data access

custom or standard API packages

read data

update data

new schema for web application

synonym for views

synonym for packages

Model classes

(business logic)

View templates

(HTML, Javascript)

Controller classes

(incoming request

processing)

SQLselects

update datathrough API

Browser

HTTP request

HTML result

custom tables for web

application

SQL

Typical application

server processes

Application server

Apache

HAproxy balancer

HTTP

HTTPS

Mongrel Mongrel Mongrel...

HTTPHTTP HTTP

Oracle DB

Memcached

SQL SQL SQL

TCP TCP TCP

Thank You!

http://blog.rayapps.comhttp://github.com/rsim