Ruby on Rails框架程序連接MongoDB的教程
前邊有介紹mongodb的安裝以及ror項(xiàng)目的搭建,現(xiàn)在進(jìn)行一下整合。
1.創(chuàng)建項(xiàng)目
創(chuàng)建項(xiàng)目時(shí)不再使用rails active_record支持
rails new todo -O
2.我們將要使用MongoMapper來驅(qū)動(dòng)MongoDB到Rails
編輯GemFile,增加下面的內(nèi)容
gem"mongo_mapper"
然后 執(zhí)行 bundle install 安裝gem
bundle install
3.添加數(shù)據(jù)庫(kù)鏈接
在config/initializer下面新建一個(gè)mongo.rb文件,指定全局的數(shù)據(jù)庫(kù)信息:
MongoMapper.connection = Mongo::Connection.new('localhost', 27017) MongoMapper.database ='todo'#通過指定Rails運(yùn)行環(huán)境參數(shù),我們可以在不同的運(yùn)行環(huán)境下創(chuàng)建互不干擾的數(shù)據(jù),為了簡(jiǎn)單起見,沒有為不同的環(huán)境指定不同的數(shù)據(jù)
if defined?(PhusionPassenger) PhusionPassenger.on_event(:starting_worker_process)do|forked| MongoMapper.connection.connectifforked end end
完成以上步驟后,啟動(dòng)程序:
$ rails server
**Notice: C extension not loaded. This is required for optimum MongoDB Ruby driver performance. You can install the extension as follows:
gem install bson_ext
If you continue to receive this message after installing, make sure that the bson_ext gem is in your load path and that the bson_ext and mongo gems are of the same version. => Booting WEBrick => Rails 3.0.10 application starting in development on http://0.0.0.0:3000 => Call with -d to detach => Ctrl-C to shutdown server [2011-10-19 23:36:14] INFO WEBrick 1.3.1 [2011-10-19 23:36:14] INFO ruby 1.9.2 (2011-07-09) [x86_64-linux] [2011-10-19 23:36:14] INFO WEBrick::HTTPServer#start: pid=19595 port=3000
從上面輸出中可以看到bson_ext庫(kù)沒有加載。按照提示安裝該庫(kù)即可(別忘了在gemfile中添加gem):
再次啟動(dòng)程序,Notice提示消息消失,啟動(dòng)正常。在瀏覽器輸入:http://127.0.0.1:3000,就可以看到如下頁(yè)面
4.添加頁(yè)面和處理邏輯
通過rails的generate命令來生成頁(yè)面、控制器和模型層文件(個(gè)人還是喜歡自己手動(dòng)創(chuàng)建,這里為了演示方便)
rails generate scaffold project name:string --orm=mongo_mapper
由于我們使用mongo作為數(shù)據(jù)庫(kù)。那么,我們需要把ActiveRecord的model,改成MongoMapper的類型,也就是把繼承關(guān)系從ActiveRecord::Base變成MongoMapper::Document。我們使用key這個(gè)方法標(biāo)明該MongoMapper的字段屬性。我們的屬性是name,再加上這個(gè)字段的類型String,那么定義如下:
classProject include MongoMapper::Document key:name,String end
通過以上的修改,我們就已經(jīng)擁有了所有添加,更新,刪除和列表的操作
5.數(shù)據(jù)查看
可以通過命令mongo進(jìn)入mongodb數(shù)據(jù)庫(kù)進(jìn)行數(shù)據(jù)的查詢
mongo //進(jìn)入數(shù)據(jù)庫(kù) use todo //切換庫(kù) db.projects.find() //執(zhí)行查詢
MongoMapper和ActiveRecord是完全相同的。甚至,MongoMapper還是支持ActiveRecord的驗(yàn)證方式如下
validates_presence_of:name
由于MongoDB沒有schema-less(數(shù)據(jù)版本記錄)我們可以非常容易的添加和更改model的屬性,而不需要執(zhí)行任何migrations的操作。比如,我們需要添加一個(gè)priority的屬性,我們僅僅需要的是修改Project model如下:
classProject include MongoMapper::Document key:name,String,:required=>true key:priority,Integer end
表之間的關(guān)聯(lián)對(duì)于MongoDB這里稍微有點(diǎn)區(qū)別,我們需要ObjectId類型來存儲(chǔ)所有id。
至于,處理不同表之前的關(guān)聯(lián),我們可以像ActiveRecord一樣定義belongs_to,當(dāng)然,稍微有點(diǎn)不同,在Project中我們需要定義has_many :tasks,在MongoMapper中需要用many代替。
我目前也就做到這里。有時(shí)間再去深入研究其他的功能。
PS:Ruby編寫MongoDB備份腳本(fsync & lock)
#!/usr/local/bin/ruby # date: 06-12-2014 # auther: lucifer # use fsync and lock to the file-system before backup the file-system # mongo-ruby-driver version > 1.10.0 require 'mongo' require 'fileutils' require 'date' include Mongo include BSON # the members of replcation-set # test mongodb server version 2.6.0 # host = "192.168.11.51" # The port of members # If the port is 27017 by default then otherport don't need to assignment # otherport = "" # port = otherport.length != 0 ? otherport : MongoClient::DEFAULT_PORT # opts = {:pool_size => 5, :pool_timeout => 10} # Create a new connection # client = MongoClient.new(host, port, opts) uri_string = "mongodb://caoqing:xxxxxxxx@x.x.x.x:27017/admin" client = MongoClient.from_uri(uri = "#{uri_string}") db = client['admin'] # fsync and lock the database cmd = OrderedHash.new cmd[:fsync] = 1 cmd[:lock] = true # p cmd db.command(cmd) # datafile path d = "/var/lib/mongo" # dir = Dir.new("#yc2omgq") # entries = dir.entries # entries.delete_if { |entry| entry =~ /^\./} # convert the relative path to the full path # entries.map! { |entry| File.join(dir.path, entry) } # maintain only the type of file # entries.delete_if { |entry| !File.file?(entry) } # p entries start = Date.today.to_s prev = (Date.today - 7).to_s dest = "/backup/#{start}" sour = "/backup/#{prev}" FileUtils.rm_rf("#{sour}") if File::exist?("#{sour}") Dir.mkdir("#{dest}", 0755) unless File::exist?("#{dest}") FileUtils.cp_r Dir.glob("#22qmucg/**"), dest if client.locked? puts "*" * 20 puts "\tbackup complete" puts "*" * 20 # DB::SYSTEM_COMMAND_COLLECTION # unlock the database db["$cmd.sys.unlock"].find_one client.close
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