DELIMITER //

CREATE PROCEDURE count_trainers_with_skill(IN description varchar(50))
BEGIN
SELECT Skill.Description ,count(Trainer.TrainerID) as NumOfTrainers
FROM Trainer, Skill, CertifiedTrainer
WHERE (Trainer.TrainerID=CertifiedTrainer.TrainerID) and CertifiedTrainer.SkillID =  Skill.SkillID and Skill.Description =description group by Skill.Description ;
END 
//
DELIMITER ;

/*Call for procedure with parameter*/
CALL count_trainers_with_skill("Shampooing");