Practice Quiz: Keys & Relationships in Databases

 

🧪 Practice Quiz: Keys & Relationships in Databases

Level: Beginner
Purpose: Reinforce concepts from Part 4
Format: 5 multiple choice questions + answers at the end

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🔸 Quiz Questions

1. What is the primary purpose of a Primary Key in a database table?
A. To store large files
B. To create duplicate records
C. To uniquely identify each record
D. To format column headers

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2. Which of the following can be a valid Primary Key?
A. A student’s name
B. A unique ID number like StudentID
C. A subject name
D. A course title

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3. What is a Foreign Key used for?
A. To store passwords securely
B. To make a copy of the table
C. To connect two tables by referencing a Primary Key
D. To delete data from another table

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4. In a relationship between Students and Results, which table usually contains the Foreign Key?
A. Students
B. Results
C. Teachers
D. Courses

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5. True or False: A Foreign Key must always refer to a column that is a Primary Key in another table.

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✅ Answers

1. C

2. B

3. C

4. B

5. True

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📝 Mini Assignment: Create Your Own Tables and Define Keys

Objective: Apply what you've learned by designing two simple tables with a relationship.

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📌 Instructions:

1. Create a Students table with the following columns:

   • StudentID (Primary Key)

   • Name

   • Class

2. Create a Marks table with the following columns:

   • MarkID (Primary Key)

   • StudentID (Foreign Key – linked to Students table)

   • Subject

   • Score

3. Write the SQL commands to create both tables and define the keys.

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💡 Optional Challenge:

Insert sample data into both tables (at least 2 students and 3 marks) and write a query to display student names along with their subjects and scores.

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Find solution to the assignment in next post.

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