BitWithBite
SQL Worksheet
🗃 Database Design & ERDs
SCORE___ / 20
NameClassDate
After this worksheet you can
Model entities and relationshipsDraw ERDsOne-to-many vs many-to-manyJunction tables📚 Quick Recap
Good database design determines whether your queries are fast or slow, your data is clean or corrupt. Learn how to model real-world entities, define relationships, and enforce data integrity with foreign keys.
🧠 Section A · Concept Check ● BEGINNER 4 × 1 = 4
1An ERD shows:
2One customer, many orders is:
3Many-to-many needs a:
4students-courses is naturally:
🧮 Section B · Problem Solving ● INTERMEDIATE 2 + 3×3 = 11
5A real-world thing (user, order) is an .
61:N means one parent, many .
7Design tables for authors and books (an author writes many books).
8Design students-courses enrolment.
9Why not store a list of course ids in one column?
🚀 Section C · Challenge ● CHALLENGE 5
10What relationship is passport-person?
💭 Reflection — the most useful thing I learned:
A ___/4 B ___/11 C ___/5 Total ___/20
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✂ answer key — fold or cut before handing out
1-A 2-B 3-A 4-C | 5 entity 6 children 7 = authors(id,...), books(id, author_id FK, ...) 8 = students, courses, enrolments(student_id, course_id) 9 = Breaks 1NF - impossible to query/join properly | 10 = 1:1