meter varias claves foranes

[superweb360]

Este ejemplo es más claro que el primero:

Código SQL:

CREATE TABLE AuthorBook(
    AuthID SMALLINT NOT NULL,
    BookID SMALLINT NOT NULL,
    PRIMARY KEY (AuthID, BookID),
    FOREIGN KEY (AuthID) REFERENCES Authors (AuthID) ON DELETE CASCADE ON UPDATE CASCADE,
    FOREIGN KEY (BookID) REFERENCES Books (BookID) ON DELETE CASCADE ON UPDATE CASCADE
  )
  ENGINE=INNODB;