Ruby 连接 Mysql – MySql2

Ruby 连接 Mysql – MySql2

        Ruby 连接 Mysql - MySql2

前面一章节我们介绍了 Ruby DBI 的使用。这章节我们技术 Ruby 连接 Mysql 更高效的驱动 mysql2,目前也推荐使用这种方式连接 MySql。

安装 mysql2 驱动:

gem install mysql2

你需要使用 –with-mysql-config 配置 mysql_config 的路径,如: –with-mysql-config=/some/random/path/bin/mysql_config。

连接

连接数据库语法如下:

更多参数可以查看 http://api.rubyonrails.org/classes/ActiveRecord/ConnectionAdapters/MysqlAdapter.html

client = Mysql2::Client.new(:host => "localhost", :username => "root")

查询

results = client.query("SELECT * FROM users WHERE group='githubbers'")

特殊字符转义

escaped = client.escape("gi'thu\"bbe\0r's")

results = client.query("SELECT * FROM users WHERE group='#{escaped}'")

计算结果集返回的数量:

results.count

迭代结果集:

results.each do |row|

row 是哈希

键值是数据库字段

值都是对应 MySQL中数据

puts row["id"] # row["id"].class == Fixnum

if row["dne"] # 不存在则是 nil

puts row["dne"]

end

end

实例

!/usr/bin/ruby -w

require 'mysql2'

client = Mysql2::Client.new(

:host => '127.0.0.1', # 主机

:username => 'root', # 用户名

:password => '123456', # 密码

:database => 'test', # 数据库

:encoding => 'utf8' # 编码

)

results = client.query("SELECT VERSION()")

results.each do |row|

puts row

end

以上实例运行输出结果为:

{"VERSION()"=>"5.6.21"}

连接选项

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

)

更多内容请参阅:http://www.rubydoc.info/gems/mysql2/0.2.3/frames