Question 1

-- Find the maker or makers of PCs with at least three different speeds. -- If more than one, order by maker. -- hint: use a having clause containing a count(distinct ) function.

part 2

-- Find those makers of at least two different computers (PCs or -- laptops) with speeds of at least 2.80. Order the list by maker. -- hint: use a subquery that does a UNION of the pc and laptop tables.

part 3

-- Find the maker(s) of the computer (PC or laptop) with the highest -- speed. If there are multiple makers, list all of them and order by maker.

Schema used -

create schema product;

use product;

create table product ( maker char(5) not null, model char(4) primary key, type char(10) not null );

create table pc ( model char(4) primary key, speed decimal(8,2) not null, ram int not null, hd int not null, price int );

create table laptop ( model char(4) primary key, speed decimal(8,2) not null, ram int not null, hd int not null, screen decimal(8,2) not null, price int not null );

create table printer ( model char(4) primary key, color boolean not null, type char(10) not null, price int not null );