Hapus data persimpangan secara otomatis bersama dengan DELETE catatan?

Deklarasikan tindakan referensial:ON DELETE CASCADE, misalnya:

CREATE TABLE user (
    user_id int PRIMARY KEY
);

CREATE TABLE offer (
    offer_id int PRIMARY KEY
);

CREATE TABLE user_offer (
    user_id int,
    offer_id int,
    PRIMARY KEY (user_id, offer_id),
    FOREIGN KEY (user_id) REFERENCES user (user_id) ON DELETE CASCADE,
    FOREIGN KEY (user_id) REFERENCES offer (offer_id) ON DELETE CASCADE
);

[SQL Fiddle]

Cukup menarik, tampaknya menentukan tindakan referensial dalam sintaks kunci asing "shorthand" tidak berfungsi (dikonfirmasi di bawah MySQL 5.5.30, 5.6.6 m9). Berikut ini diuraikan, tetapi ketika user dihapus, user_offer yang sesuai tidak terhapus:

CREATE TABLE user_offer (
    user_id int REFERENCES user (user_id) ON DELETE CASCADE,
    offer_id int REFERENCES offer (offer_id) ON DELETE CASCADE,
    PRIMARY KEY (user_id, offer_id)
);