What is the purpose of a foreign key in a relational database?
A
Speed up query execution
B
Store binary large objects
C
Establish a link between two tables
D
Encrypt sensitive data
Correct Answer: Option C — Establish a link between two tables
Explanation:
A foreign key is a column or set of columns in one table that references the primary key of another table, establishing a relationship between the two. This ensures referential integrity by linking related data across different tables.