In the previous units, we covered how primary keys uniquely identify records and foreign keys create links between tables, forming different types of relationships.

Now, let's practice applying these concepts to different database scenarios.

Engagement Message

Ready to become a key master?

Type

Sort Into Boxes

Practice Question

Consider an Orders table with the columns order_id, customer_id, order_date, and product_id. Sort these columns into the correct key type for this table.

Labels

• First Box Label: Primary Key
• Second Box Label: Foreign Key

First Box Items

• order_id

Second Box Items

• customer_id
• product_id

Type

Multiple Choice

Practice Question

Which of the following is a true statement about a foreign key?

A. It must be unique within its table. B. It cannot contain duplicate values. C. It must refer to a primary key value in another table. D. It cannot be NULL.

Suggested Answers

• A
• B
• C - Correct
• D