Create an ERD for a car dealership. The dealership sells both new and used cars, and it operates a service facility (see Figure B.2). Base your design on the following business rules:
A salesperson may sell many cars, but each car is sold by only one salesperson.
A customer may buy many cars, but each car is bought by only one customer.
A salesperson writes a single invoice for each car he or she sells.
A customer gets an invoice for each car he or she buys.
A customer may come in just to have his or her car serviced; that is, a customer need not buy a car to be classified as a customer.
When a customer takes one or more cars in for repair or service, one service ticket is written for each car.
The car dealership maintains a service history for each of the cars serviced. The service records are referenced by the car’s serial number.
A car brought in for service can be worked on by many mechanics, and each mechanic may work on many cars.
A car that is serviced may or may not need parts (e.g., adjusting a carburetor or cleaning a fuel injector nozzle does not require providing new parts).
SELECT NAME FROM
WHERE QUOTA >=
(SELECT TARGET FROM OFFICES WHERE CITY = 'LAHORE')
Select empl_num, commision from SALESRESP where months_between(sysdate, joining_date) < 24 AND sal > 50000;
update salesresp set commission = update_commision;
dbms_output.put_line('Updated Commision ' || commision);