MySQLにアクセス

db.rb

require 'mysql2'
require 'mysql2-cs-bind'

# Mysqlドライバの設定
db = Mysql2::Client.new(
  host: 'localhost',
  port: 3306,
  username: 'root',
  password: '',
  database: 'sample',
  reconnect: true,
)

result = db.xquery("SELECT * FROM infos")
infos = result.to_a

puts infos[0]["name"]

gem install mysql2 mysql2-cs-bind
してください