In a relational database a referential integrity constraint can be done using
Answer options
A
primary key
B
foreign key
C
secondary key
D
compose key
Correct answer: foreign key
Explanation
Referential integrity is enforced in a relational database through a foreign key constraint, which ensures that a value in one table's column must exist as a primary key in the referenced table. Primary keys enforce entity integrity (uniqueness/not-null), not referential integrity across tables.