CREATE TABLE players (
  id INT NOT NULL PRIMARY KEY AUTO_INCREMENT,
  name VARCHAR(32),
  level INT,
  job_id INT
);

CREATE TABLE jobs (
  id INT NOT NULL PRIMARY KEY AUTO_INCREMENT,
  job_name VARCHAR(10),
  vitality INT,
  strength INT,
  agility INT,
  intelligence INT,
  luck INT
);

INSERT INTO players(name,level,job_id)
VALUES
  ("Sinatra",12,6),
  ("ケン",7,2),
  ("リン",1,1),
  ("ユウ",3,3),
  ("クレア",10,4),
  ("ショウ",5,2),
  ("さくら",7,1),
  ("ジャック",5,4),
  ("ロック",12,6),
  ("じゅん",1,NULL);

INSERT INTO jobs(job_name, vitality, strength, agility, intelligence, luck)
VALUES
  ("戦士",8,8,4,4,3),
  ("盗賊",3,3,8,5,7),
  ("狩人",5,5,7,5,4),
  ("魔法使い",3,2,6,8,6),
  ("僧侶",5,5,3,7,5),
  ("勇者",10,10,10,10,10);

# rubyでmysqlに接続する
require 'mysql2'

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

sql = "SELECT * FROM players"
statement = client.prepare(sql)
results = statement.execute()

results.each do |row|
    p row
end

- [SQL入門編1: SQLの基本文法を学ぶ(全7回) | プログラミング学習ならpaizaラーニング
https://paiza.jp/works/sql/primer/beginner-sql1-cloud

- phpMyAdminの使い方
http://www.dbonline.jp/phpmyadmin/

- [Ruby mysql2のメモ - かもメモ]
http://chaika.hatenablog.com/entry/2016/04/01/083000
- [ruby から mysql へアクセスする - KRAKENBEAL RECORDS]
http://krakenbeal.blogspot.jp/2013/02/ruby-mysql.html