Topic $1$:

$1$a$.$

i$.$ Construct an E$-$R diagram for a hospital with a set of patients and a set of medical

doctors. Associate with each patient a log of the various tests and examinations

conducted.

Ensure that you document all assumptions that you make about the mapping constraints.

Ensure that the entities, actions, attributes, and relationships are all shown.

ii$.$ Explain the distinctions among the terms primary key, candidate key, and super key.

$1$b$.$ For the following relation schema:

employee $($employee$-$name, street, city$)$

works $($employee$-$name, company$-$name, salary$)$

company $($company$-$name, city$)$

manages $($employee$-$name, manager$-$name$)$

Give an expression in SQL for each of the following queries:

i$.$ Find the names, street addresses, and cities of residence for all employees who work

for 'First Halal Bank Corporation' and earn more than $$20,000.$

ii$.$ Find the names of all employees in the database who earn more than every employee

of 'Barakah Bank Corporation'. Assume that all people work for at most one company.

iii. Find the names of all employees in the database who live in the same cities but on

different streets as do their managers.