Introduction
Databases are one of the most important topics in IB Computer Science, especially for Paper 2. Whether you’re sitting SL or HL, you’ll face questions on relational databases, SQL queries, and applied database design. The good news? With focused revision, databases are one of the most predictable and high-scoring areas of the exam.
This guide will walk you through how to revise databases effectively, the key concepts you must know, and the best strategies to score top marks.
Quick Start Checklist
- Review relational database basics (tables, keys, relationships).
- Practice SQL queries daily (SELECT, INSERT, UPDATE, DELETE).
- Learn the advantages of normalization.
- Use past Paper 2 questions for practice.
- Apply database concepts to real-world examples (e.g., e-commerce, schools).
Key Database Topics for IB Computer Science
1. Relational Database Basics
- Tables: rows = records, columns = fields.
- Primary key: uniquely identifies a record.
- Foreign key: creates relationships between tables.
👉 Why it matters: These are easy marks if you use correct terminology.
2. Normalization
- 1NF: remove duplicate columns.
- 2NF: eliminate partial dependencies.
- 3NF: remove transitive dependencies.
👉 Strategy: Be ready to explain the purpose of normalization — reducing redundancy and improving efficiency.
3. SQL Queries
You should confidently write:
SELECT * FROM Students WHERE Grade > 5;INSERT INTO Teachers VALUES (101, "Smith", "Math");UPDATE Orders SET Status = "Shipped" WHERE OrderID = 45;DELETE FROM Accounts WHERE Balance < 0;
👉 Exam tip: Examiners allow logical queries even if your syntax isn’t perfect, as long as intent is clear.
4. Entity-Relationship Diagrams (ERDs)
- Entities = tables.
- Attributes = fields.
- Relationships = one-to-many, many-to-many.
👉 Tip: Always label relationships clearly. A neat ERD often earns easy marks.
5. Advantages of Databases
- Data integrity and consistency.
- Easier data retrieval and analysis.
- Security and controlled access.
👉 Why: Paper 2 often asks for evaluation — be ready with advantages/disadvantages.
How to Revise Databases in 3 Steps
Step 1: Revise Core Notes
Use IB Computer Science Notes to review database concepts. Focus on definitions, diagrams, and examples.
Step 2: Drill SQL Practice
Write 5–10 SQL queries daily. Use simple scenarios like school databases or online stores. Aim for clarity, not complexity.
Step 3: Apply to Past Papers
Do at least two past Paper 2 questions involving databases. Review mark schemes to see how answers are structured.
Common Mistakes in Database Questions
- Mixing up primary and foreign keys.
- Forgetting semicolons in SQL (while IB may forgive, it shows carelessness).
- Overcomplicating queries — stick to basic logic.
- Ignoring normalization benefits.
- Drawing unclear or unlabeled ER diagrams.
Frequently Asked Questions
1. Do I need to memorize SQL syntax exactly?
Not perfectly. Examiners care more about logical structure than strict formatting. But practice enough so your queries look consistent.
2. How many database questions appear in Paper 2?
Almost every Paper 2 includes at least one database question, making it one of the most predictable areas to revise.
3. What’s more important: SQL or ER diagrams?
Both matter, but SQL carries more weight. ER diagrams often appear as short-answer questions, while SQL queries are worth more marks.
4. Should I practice database questions without a computer?
Yes — the IB exam is handwritten. Practice writing queries and diagrams on paper, not just on a laptop.
5. How much time should I spend revising databases?
At least 20–25% of your Paper 2 revision should go into databases. It’s a reliable way to boost your score.
Conclusion
Databases are one of the best areas to target in your IB Computer Science revision. By mastering relational design, practicing SQL, and applying concepts to real-world scenarios, you can pick up consistent marks in Paper 2.
If you’re short on time, focus on SQL queries, ER diagrams, and normalization — they appear in almost every exam. For structured explanations and examples, see IB Computer Science Notes, and check our guide on How to Get a 7 in IB Computer Science.
