当我尝试使用外键创建表时，出现未知数据类型错误。我不确定我的语法是否错误？确切的错误消息是：第14行出现错误4161（HY000）：未知数据类型：'t_name'，表示P1_Player表是引发错误的位置。

DROP TABLE IF EXISTS P1_Player;
DROP TABLE IF EXISTS P1_Plays;
DROP TABLE IF EXISTS P1_Coach;
DROP TABLE IF EXISTS P1_Game;
DROP TABLE IF EXISTS P1_Team;

create table P1_Team
       (t_name          varchar(20),
        primary key (t_name)
        );

create table P1_Player
       (fname           varchar(20),
        lname           varchar(20),
        DOB             date,
        jersey_#        int,
        t_name          varchar(20),
        primary key (fname, lname, DOB),
        foreign key (t_name) references P1_Team (t_name)
                on delete cascade
        );

create table P1_Coach
       (fname            varchar(20),
        lname            varchar(20),
        t_name           varchar(20),
        foreign key (t_name) references P1_Team (t_name)
                on delete cascade
        );

create table P1_Game
       (t_name           varchar(20),
        game_date         date,
        game_time         time,
        primary key (t_name, game_date, game_time),
        foreign key (t_name) references P1_Team (t_name)
                on delete cascade
        );
create table P1_Plays
       (t_name            varchar(20),
        game_date         date,
        game_time         time,
        primary key (t_name, game_date, game_time),
        foreign key (t_name, game_date, game_time) references P1_Game (t_name, game_date,    game_time)
                on delete cascade
        );