Relational Data Concepts

Question 1

What is a primary key?

Answer 1

• A column or combination of columns
• Uniquely identifies each row in a table
• Cannot contain NULL values
• Must be unique across all records
• Used to maintain data integrity

Question 2

What is referential integrity?

Answer 2

• Ensures relationships between tables remain consistent
• Foreign key must reference a valid primary key
• Prevents orphaned records
• Maintains data accuracy
• Core concept in relational databases