ITPEC IP April 2025 Question 26

The Customers table needs both Employee code and Region code as foreign keys — those keys provide the links needed to obtain both names in the joined result.

Table A includes Customer data plus Employee name and Region name. Employee name can be obtained by joining Customers.Employee code to Employees in charge.Employee code. Region name similarly requires Customers.Region code to join to Regions.Region code. Customer code remains the Customers primary key.

Answer (d)

Why not others:
- (a) has neither foreign key, so it cannot join to either reference table
- (b) can obtain Employee name but not Region name
- (c) can obtain Region name but not Employee name

Key rule: A foreign key stores the referenced table's primary-key value; every independent lookup represented in a join needs a corresponding relationship.

AI-generated — may contain errors