CREATE TABLE sport (
    sport_id    	INT    AUTO_INCREMENT,
    sport_name 		varchar(50) NOT NULL,
    
    PRIMARY KEY (sport_id),
    UNIQUE INDEX sport_name_ak(sport_name)
 )ENGINE=INNODB
;



CREATE TABLE league (
    league_id    INT    AUTO_INCREMENT,
    league_name  varchar(20) NOT NULL,
    sport_id     INT    NOT NULL,
    
    PRIMARY KEY (league_id), 
    FOREIGN KEY (sport_id) REFERENCES sport(sport_id),
    UNIQUE INDEX league_name_ak(league_name, sport_id)
)ENGINE=INNODB
;


CREATE TABLE team (
    team_id    INT    AUTO_INCREMENT,
    team_name  varchar(20) NOT NULL,
    league_id     INT    NOT NULL,
	city       varchar(30)  NOT NULL,    
	
    PRIMARY KEY (team_id), 
    FOREIGN KEY (league_id) REFERENCES league(league_id),
    UNIQUE INDEX team_name_ak(team_name, league_id)
)ENGINE=INNODB
;

