create table A(id int not null primary key) engine=innodb;create 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;create 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;insert into A values(1), (2);DELETE FROM A where id = 1;DELETE FROM C where f1 = 2;DELETE FROM A where id = 1;DROP TABLE C;DROP TABLE B;DROP TABLE A;