带或不带外键的REFERENCES之间有什么区别

关于 SQLite ,带或不带外键的REFERENCES之间有什么区别?

这两者有什么区别

CREATE TABLE players_set ( 
    _id            INTEGER PRIMARY KEY AUTOINCREMENT
                           NOT NULL,
    player_id      INTEGER REFERENCES players ( _id ) ON DELETE CASCADE,
    players_set_id INTEGER REFERENCES players_set_names ( _id ) 
);

并且:

CREATE TABLE players_set ( 
    _id            INTEGER PRIMARY KEY AUTOINCREMENT
                           NOT NULL,
    player_id INTEGER,
    players_set_id INTEGER REFERENCES players_set_names ( _id ),
    FOREIGN KEY (player_id) REFERENCES players ( _id ) ON DELETE CASCADE        
);

我发现了另一个问题: Difference between using REFERENCES with and without FOREIGN KEY?

我读到了 the documentation ,但我没有说清楚。

准确地说,我正在使用SQLite Android (因此是标签)。我不知道这是否会有什么不同,但如果它有自己的怪癖,我会很有用地了解一下。