ruby安装mysql2,pg模块

$ sudo gem install mysql2 --'--with-mysql-config=/opt/mysql/bin/mysql_config'mysql

测试sql

$ cat testmysql2.rb 数据库

require 'mysql2'
client = Mysql2::Client.new(:host => "127.0.0.1", :username => "用户名",:password=>"密码",:database=>"数据库名");
results = client.query("select * from 表");
results.each do |hash|
  puts hash.map { |k,v| "#{k} = #{v}" }.join(", ")
end

安装pg模块ruby

sudo gem install pg --'--with-pg-config=/opt/PostgreSQL/9.4/bin/pg_config'测试