http://code.tutsplus.com/articles/an-introduction-to-stored-procedures-in-mysql-5–net-17843
Tutorial muy completo:
https://www.mysqltutorial.org/mysql-stored-procedure-tutorial.aspx/
https://manuales.guebs.com/mysql-5.0/stored-procedures.html
https://proyectoa.com/anadir-y-usar-procedimiento-almacenado-stored-procedure-en-mysql-server/
