Question

I am wanting to create a stored procedure that accepts the team name and year and returns the number of players in that particular team for that particular year. I am working with MYSQL and listed below are the tables I am using:

Person     (personID, name, phone, email, year)
Player     (personID, dateOfBirth, school)
playerTeam (personID, teamID)
Team       (teamID, teamName, ageGroup)

So far I have tried joining the tables and couting the personID only where teamName and Person.year = the input parameters but to no avail. Any ideas?

After submitting this question, using trial and error, I was able to get this to work using the following statements:

DELIMITER //

CREATE PROCEDURE teamSize (IN team VARCHAR (30), IN YEAR INT) 
BEGIN
          SELECT 
                    COUNT(Person.personID) NumOfPlayers 
          FROM
                    Person AS p,
                    Player,
                    playerTeam,
                    Team 
          WHERE Person.personID = Player.personID 
                    AND Player.personID = playerTeam.personID 
                    AND Team.teamID = playerTeam.teamID 
                    AND Team.teamName = team 
                    AND Person.year = YEAR ;
END //

DELIMITER ;

CALL teamSize('Pirates', 1991);

Is there anyway to simplify this using joins etc as at the moment its a bit messy.

Answer 1

I’m not sure if you want like this:

DELIMITER //

CREATE PROCEDURE GetPlayerCount (
          IN oTeamName VARCHAR (50),
          IN oYear INT
) AS 
BEGIN
          SELECT 
                    COUNT(a.PersonID) NoOfPlayers 
          FROM
                    Person a 
                    INNER JOIN PlayerTeam b 
                              ON a.PersonID = b.PersonID 
                    INNER JOIN Team c 
                              ON b.TeamID = c.TeamID 
          WHERE b.TeamName = oTeamName 
                    AND a.Year = oYear ;
END //

DELIMITER ;

but i think this is want you want.

Usage:

CALL GetPlayerCount('TeamDog', 2012);