1
create table A(id int not null primary key) engine=innodb;
2
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;
3
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;
4
insert into A values(1), (2);
5
DELETE FROM A where id = 1;
6
DELETE FROM C where f1 = 2;
7
DELETE FROM A where id = 1;