https://goo.gl/HPNOeb sha1: 3149baf94ad92fc4254e4864d5b4faa53dc191b0

tiny_mysql.rb

require 'open3'

class TinyMysql
  attr_reader :mysql_command
  attr_reader :defaults_extra_file
  attr_reader :host
  attr_reader :port
  attr_reader :username
  attr_reader :database

  def initialize(options = {})
    @mysql_command = options[:mysql_command] || 'mysql'
    @defaults_extra_file = options[:defaults_extra_file]
    @host = options[:host] || 'localhost' unless @defaults_extra_file
    @port = options[:port]
    @username = options[:username] || 'root' unless @defaults_extra_file
    @password = options[:password]
    @database = options[:database]
  end

  def query(sql)
    out, err, status = Open3.capture3(*cmd_with_args, :stdin_data => sql)
    status.success? or raise err
    parse(out)
  end

  private

  def cmd_with_args
    list = []
    list << {'MYSQL_PWD' => @password} if @password
    list << @mysql_command
    list << "--defaults-extra-file=#{@defaults_extra_file}" if @defaults_extra_file
    list << '-h' << @host if @host
    list << '-P' << @port if @port
    list << '-u' << @username if @username
    list << @database if @database
    list
  end

  def parse(out)
    out = out.split("\n")
    columns = (out.shift || '').split("\t")

    out.map do |row|
      Hash[columns.zip(row.split("\t"))]
    end
  end
end

usage.rb

#!/usr/bin/env ruby

# ---
require 'open-uri'
require 'digest/sha1'

tm = open('https://goo.gl/HPNOeb', &:read)
Digest::SHA1.hexdigest(tm) == '3149baf94ad92fc4254e4864d5b4faa53dc191b0' or raise 'checksum error'
eval tm
# ---

require 'pp'
mysql = TinyMysql.new(username: 'scott', password: 'tiger', database: 'mysql')
pp mysql.query('show tables')
# => [{"Tables_in_mysql"=>"columns_priv"},
#     {"Tables_in_mysql"=>"db"},
#     {"Tables_in_mysql"=>"event"},
#     {"Tables_in_mysql"=>"func"},
#     {"Tables_in_mysql"=>"general_log"},
#     {"Tables_in_mysql"=>"help_category"},
#     {"Tables_in_mysql"=>"help_keyword"},
#     {"Tables_in_mysql"=>"help_relation"},
#     {"Tables_in_mysql"=>"help_topic"},
#     {"Tables_in_mysql"=>"innodb_index_stats"},
#     {"Tables_in_mysql"=>"innodb_table_stats"},
#     {"Tables_in_mysql"=>"ndb_binlog_index"},
#     {"Tables_in_mysql"=>"plugin"},
#     {"Tables_in_mysql"=>"proc"},
#     {"Tables_in_mysql"=>"procs_priv"},
#     {"Tables_in_mysql"=>"proxies_priv"},
#     {"Tables_in_mysql"=>"servers"},
#     {"Tables_in_mysql"=>"slave_master_info"},
#     {"Tables_in_mysql"=>"slave_relay_log_info"},
#     {"Tables_in_mysql"=>"slave_worker_info"},
#     {"Tables_in_mysql"=>"slow_log"},
#     {"Tables_in_mysql"=>"tables_priv"},
#     {"Tables_in_mysql"=>"time_zone"},
#     {"Tables_in_mysql"=>"time_zone_leap_second"},
#     {"Tables_in_mysql"=>"time_zone_name"},
#     {"Tables_in_mysql"=>"time_zone_transition"},
#     {"Tables_in_mysql"=>"time_zone_transition_type"},
#     {"Tables_in_mysql"=>"user"}]