Trouble adding Foreign Key Constraint (error ORA-02270: no matching unique or primary key for this column-list) - sql

Question

I am learning how to create a small and simple database for class with Primary Key and Foreign Key restraints. I am getting ORA-02770 when attempting to run my ALTER TABLE statement, which as I understand is notifying me that the column I am referencing in the outside table is not listed as a primary key constraint. However, from what I can see my syntax is correct naming the primary keys in my CREATE TABLES statements. I searched inside the all_cons_columns table for the player_info table and it showed the primary keys listed as well. Could I get some guidance? Listed below is my current script:
CREATE TABLE Player_Game
( school varchar2(30),
player_number number(2,0),
game_number number(1,0),
CONSTRAINT playergame_pk PRIMARY KEY (school, player_number,game_number)
);
CREATE TABLE School
( school varchar2(30),
city varchar2(30),
coach varchar2(30),
team_name varchar2(30),
win_record number (2,0),
loss_record number (2,0),
CONSTRAINT school_pk PRIMARY KEY (school)
);
CREATE TABLE Game
( school varchar2(30),
game_number number(1,0),
game_date DATE,
game_score varchar2(15),
CONSTRAINT game_pk PRIMARY KEY (school, game_number)
);
CREATE TABLE player_info
( school varchar2(30),
player_number number(2,0),
player_name varchar2(25),
CONSTRAINT playerinfo_pk PRIMARY KEY (school, player_number)
);
CREATE TABLE city
( city varchar2(30),
population number(5,0),
CONSTRAINT city_pk PRIMARY KEY (city)
);
/*Here is the failing alter command */
ALTER TABLE Player_Game
ADD CONSTRAINT playergame_fk FOREIGN KEY (school) REFERENCES game(school);

Answer 1

You have incorrect column list in playergame_fk in the alter table statement. The column list of the foreign key must exactly match with the column list of the primary key it is referencing to.
Primary Key column list is school, game_number, therefore, your foreign key must have the same columns:
ALTER TABLE Player_Game
ADD CONSTRAINT playergame_fk FOREIGN KEY (school, game_number)
REFERENCES game(school, game_number);