1create table A(id int not null primary key) engine=innodb;
2create table B(id int not null auto_increment primary key, f1 int not null, foreign key(f1) references A(id) on delete cascade) engine=innodb;
3create table C(id int not null auto_increment primary key, f1 int not null, foreign key(f1) references B(id) on delete cascade) engine=innodb;
4insert into A values(1), (2);
5DELETE FROM A where id = 1;
6DELETE FROM C where f1 = 2;
7DELETE FROM A where id = 1;
8DROP TABLE C;
9DROP TABLE B;
10DROP TABLE A;
11