Where you get dratini in Pokemon Ruby?

Its super easy to get one, you only need 1 link cable, Pokemon firered or leafgreen that can trade Pokemon to ruby, Sapphire and emerald and a dratini. If you don't have a dratini at Pokemon firered or leafgreen, you have to look at www.serebii.net and look at poke-earth or the pokedex. I hope it helps!