dsl.rb

class SQLBuilder

  def self.method_missing(method_name, *args)
    SQLBuilder.new(method_name)
  end

  def method_missing(method_name, *args)
    @buf << method_name
    self
  end

  def build
    @buf.join(" ")
  end


  private
  def initialize(keyword)
    @buf = [keyword]
  end
end

select = SQLBuilder.select

puts select.*.from.emp.build