脱离Rails使用Activerecord

ActiveRecord 是迄今为止我所见到的最好的ORM  library ，除了DB2，支持所有的主流数据库。如果你想知道如何单独使用Activerecord，please follow me。

介绍一下我的系统环境：

OS:windows2003

DataBase: Oracle10g

Ruby: 1.8.7 (2008-05-31 patchlevel 0) [i386-mswin32]

activerecord: 2.2.2

activerecord-oracle_enhanced-adapter: 1.1.8

ruby-oci8:1.0.3

准备工作：

1.安装ruby，不用说了吧

2.安装activerecord, gem install activerecord

3.安装adapter, gem install activerecord-oracle_enhanced-adapter

4.创建一个试验目录 mkdir dbtest

ok,that's all

创建一个rb文件，内容如下

require 'rubygems'
require 'active_record'

ActiveRecord::Base.establish_connection(
  :adapter  => 'oracle_enhanced',
  :database => 'test',   #oracle service name
  :username => 'system',
  :password => 'system')

require 'rubygems'
require 'active_record'
ActiveRecord::Base.establish_connection(
:adapter  => 'oracle_enhanced',
:database => 'test',   #oracle service name
:username => 'system',
:password => 'system')  

你还可以把数据库的配置信息单独放在一个文件中，创建一个文件database.yml，内容如下

adapter:  oracle_enhanced
database: test
username: system
password: system

adapter:  oracle_enhanced
database: test
username: system
password: system

 更改rb文件为

require 'rubygems'
require 'active_record'
require 'yaml'

dbconfig = YAML::load(File.open('database.yml'))
ActiveRecord::Base.establish_connection(dbconfig)

require 'rubygems'
require 'active_record'
require 'yaml'
dbconfig = YAML::load(File.open('database.yml'))
ActiveRecord::Base.establish_connection(dbconfig)

 试一试效果

require 'rubygems'
require 'active_record'
require 'yaml'

dbconfig = YAML::load(File.open('database.yml'))
ActiveRecord::Base.establish_connection(dbconfig)

class User < ActiveRecord::Base
  set_table_name "my_user"
end

puts User.count

require 'rubygems'
require 'active_record'
require 'yaml'
dbconfig = YAML::load(File.open('database.yml'))
ActiveRecord::Base.establish_connection(dbconfig)
class User < ActiveRecord::Base
set_table_name "my_user"
end
puts User.count  

 如果你想给activerecord加上日志，可以这么做

require 'rubygems'
require 'active_record'
require 'yaml'
require 'logger'

dbconfig = YAML::load(File.open('database.yml'))
ActiveRecord::Base.establish_connection(dbconfig)
ActiveRecord::Base.logger = Logger.new(File.open('database.log', 'a'))

class User < ActiveRecord::Base
   set_table_name "my_user"
end

puts User.count

require 'rubygems'
require 'active_record'
require 'yaml'
require 'logger'
dbconfig = YAML::load(File.open('database.yml'))
ActiveRecord::Base.establish_connection(dbconfig)
ActiveRecord::Base.logger = Logger.new(File.open('database.log', 'a'))
class User < ActiveRecord::Base
set_table_name "my_user"
end
puts User.count  

这样就产生了一个database.log文件

OK，今天就到这里吧