Use the following PC Manufacturer sample DB to write these queries as well as relational algebra expression.

1. Find the model number and price of all products (of any type) made by maker B.

2. Find those makers that sell laptops, not PCs.

3. Find those makers of at least two different computers.

 Create Database ClassicExample_1; GO USE ClassicExample_1; GO CREATE TABLE Product ( Maker Char(1) NULL, Model Integer NOT NULL, Type Char (10) NULL, PRIMARY KEY (Model) ); CREATE TABLE PC ( Model Integer NOT NULL, speed Decimal (3,2) NULL, Ram Integer NULL, Hd Integer NULL, Price Integer NULL, PRIMARY KEY (Model) ); CREATE TABLE Laptop ( Model Integer NOT NULL, speed Decimal (3,2) NULL, Ram Integer NULL, Hd Integer NULL, Screen Decimal (3,1) NULL, Price Integer NULL, PRIMARY KEY (Model) ); CREATE TABLE Printer ( Model Integer NOT NULL, Color Bit NULL, Typ Char (16) NULL, Price Integer NULL, PRIMARY KEY (Model) ); GO 

USE ClassicExample_1; /* Inserting values for Product table */ Insert into Product values ('A', '1001', 'pc'); Insert into Product values ('A', '1002', 'pc'); Insert into Product values ('A', '1003', 'pc'); Insert into Product values ('A', '2004', 'laptop'); Insert into Product values ('A', '2005', 'laptop'); Insert into Product values ('A', '2006', 'laptop'); Insert into Product values ('B', '1004', 'pc'); Insert into Product values ('B', '1005', 'pc'); Insert into Product values ('B', '1006', 'pc'); Insert into Product values ('B', '2007', 'laptop'); Insert into Product values ('C', '1007', 'pc'); Insert into Product values ('D', '1008', 'pc'); Insert into Product values ('D', '1009', 'pc'); Insert into Product values ('D', '1010', 'pc'); Insert into Product values ('D', '3004', 'printer'); Insert into Product values ('D', '3005', 'printer'); Insert into Product values ('E', '1011', 'pc'); Insert into Product values ('E', '1012', 'pc'); Insert into Product values ('E', '1013', 'pc'); Insert into Product values ('E', '2001', 'laptop'); Insert into Product values ('E', '2002', 'laptop'); Insert into Product values ('E', '2003', 'laptop'); Insert into Product values ('E', '3001', 'printer'); Insert into Product values ('E', '3002', 'printer'); Insert into Product values ('E', '3003', 'printer'); Insert into Product values ('F', '2008', 'laptop'); Insert into Product values ('F', '2009', 'laptop'); Insert into Product values ('G', '2010', 'laptop'); Insert into Product values ('H', '3006', 'printer'); Insert into Product values ('H', '3007', 'printer'); /* Inserting values for PC table */ insert into PC values ('1001', '2.66', '1024', '250', '2114'); insert into PC values ('1002', '2.10', '512', '250', '995'); insert into PC values ('1003', '1.42', '512', '80', '478'); insert into PC values ('1004', '2.80', '1024', '250', '649'); insert into PC values ('1005', '3.20', '512', '250', '630'); insert into PC values ('1006', '3.20', '1024', '320', '1049'); insert into PC values ('1007', '2.20', '1024', '200', '510'); insert into PC values ('1008', '2.20', '2048', '250', '770'); insert into PC values ('1009', '2.00', '1024', '250', '650'); insert into PC values ('1010', '2.80', '2048', '300', '770'); insert into PC values ('1011', '1.86', '2048', '160', '959'); insert into PC values ('1012', '2.80', '1024', '160', '649'); insert into PC values ('1013', '3.06', '512', '80', '529'); /* Inserting values for Laptop table */ insert into Laptop values ('2001', '2.00', '2048', '240', '20.1', '3673' ); insert into Laptop values ('2002', '1.73', '1024', '80', '17.0', '949' ); insert into Laptop values ('2003', '1.80', '512', '60', '15.4', '549' ); insert into Laptop values ('2004', '2.00', '512', '60', '13.3', '1150' ); insert into Laptop values ('2005', '2.16', '1024', '120', '17.0', '2500' ); insert into Laptop values ('2006', '2.00', '2048', '80', '15.4', '1700' ); insert into Laptop values ('2007', '1.83', '1024', '120', '13.3', '1429' ); insert into Laptop values ('2008', '1.60', '1024', '100', '15.4', '900' ); insert into Laptop values ('2009', '1.60', '512', '80', '14.1', '680' ); insert into Laptop values ('2010', '2.00', '2048', '160', '15.4', '2300' ); /* Inserting values for printer table */ insert into printer values ('3001', '1', 'ink-jet', '99'); insert into printer values ('3002', '0', 'laser', '239'); insert into printer values ('3003', '1', 'laser', '899'); insert into printer values ('3004', '1', 'ink-jet', '120'); insert into printer values ('3005', '0', 'laser', '120'); insert into printer values ('3006', '1', 'ink-jet', '100'); insert into printer values ('3007', '1', 'laser', '200');