Ruby 連接 Mysql - MySql2
前面一章節(jié)我們介紹了 Ruby DBI 的使用。這章節(jié)我們技術(shù) Ruby 連接 Mysql 更高效的驅(qū)動(dòng) mysql2,目前也推薦使用這種方式連接 MySql。
安裝 mysql2 驅(qū)動(dòng):
gem install mysql2
你需要使用 –with-mysql-config 配置 mysql_config 的路徑,如: –with-mysql-config=/some/random/path/bin/mysql_config。
連接
連接數(shù)據(jù)庫(kù)語(yǔ)法如下:
# 更多參數(shù)可以查看 http://api.rubyonrails.org/classes/ActiveRecord/ConnectionAdapters/MysqlAdapter.html client = Mysql2::Client.new(:host => "localhost", :username => "root")
查詢
results = client.query("SELECT * FROM users WHERE group='githubbers'")
特殊字符轉(zhuǎn)義
escaped = client.escape("gi'thu\"bbe\0r's") results = client.query("SELECT * FROM users WHERE group='#{escaped}'")
計(jì)算結(jié)果集返回的數(shù)量:
results.count
迭代結(jié)果集:
results.each do |row| # row 是哈希 # 鍵值是數(shù)據(jù)庫(kù)字段 # 值都是對(duì)應(yīng) MySQL中數(shù)據(jù) puts row["id"] # row["id"].class == Fixnum if row["dne"] # 不存在則是 nil puts row["dne"] end end
實(shí)例
#!/usr/bin/ruby -w require 'mysql2' client = Mysql2::Client.new( :host => '127.0.0.1', # 主機(jī) :username => 'root', # 用戶名 :password => '123456', # 密碼 :database => 'test', # 數(shù)據(jù)庫(kù) :encoding => 'utf8' # 編碼 ) results = client.query("SELECT VERSION()") results.each do |row| puts row end
以上實(shí)例運(yùn)行輸出結(jié)果為:
{"VERSION()"=>"5.6.21"}
連接選項(xiàng)
Mysql2::Client.new( :host, :username, :password, :port, :database, :socket = '/path/to/mysql.sock', :flags = REMEMBER_OPTIONS | LONG_PASSWORD | LONG_FLAG | TRANSACTIONS | PROTOCOL_41 | SECURE_CONNECTION | MULTI_STATEMENTS, :encoding = 'utf8', :read_timeout = seconds, :write_timeout = seconds, :connect_timeout = seconds, :reconnect = true/false, :local_infile = true/false, :secure_auth = true/false, :default_file = '/path/to/my.cfg', :default_group = 'my.cfg section', :init_command => sql )
更多內(nèi)容請(qǐng)參閱:http://www.rubydoc.info/gems/mysql2/0.2.3/frames。
更多建議: