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create table class ( id int primary key auto_increment, name varchar(64) unique key ); create table subclass ( id int primary key auto_increment, class_id int references class(id), name varchar(64) unique key ); create table items ( id int primary key auto_increment, subclass_id int references subclass(id), name varchar(64) unique key ); insert into class (name) values ('Fruits'), ('Vegetables'); insert into subclass (class_id, name) values (1, 'Red'), (1, 'Orange'), (2, 'Green'), (2, 'Yellow'); insert into items (subclass_id, name) values (1, 'Apple'), (2, 'Pineapple'), (3, 'Cucumber'), (3, 'Carrot'); select class.name class, subclass.name subclass, items.name item from items join subclass on items.subclass_id = subclass.id join class on subclass.class_id = class.id;