$5-$ Based on the below relational schema, answer the following questions. $(20$ pts$)$

Emp$($empid: integer, empname: string, age: integer, salary: real$)$

Works$($empid: integer, deptid: integer, pcttime: integer$)$

Dept$($deptid: integer, deptname: string, budget: real, managerid: integer$)$

a$.$ Identify a foreign key involving the Dept relation. Discuss how this constraint can be

enforced when trying to delete a Dept tuple.

b$.$ Provide the SQL statements to create the relations mentioned above, ensuring to

include necessary primary and foreign key constraints.

c$.$ How would you define the Dept relation in SQL to ensure each department always

has a manager?

d$.$ Write an SQL statement to add an employee named your name with empid as your

student ID and age as your own $($or a random!$)$ age and salary of $$71,000.($important

to user your real name and student id$)$

e$.$ Write an SQL statement that applies a $9\%$ salary increase to every employee. $($with

UPDATE TABLE query$)$

f$.$ Write an SQL statement for removing a department named $\text{'}$IT$\text{'}.$ Discuss the

consequences of this action given your schema's referential integrity constraints.