1. 1 Entity-Relationship Modeling

2. 2 ER Graphical modeling technique Informal, understandable for laymen Coarse technique to design tables Provides rules of thumb for mapping to table structures

3. 3 Entities and attributes

4. 4 Relations (associations)

5. 5 Recursive relations With roles

6. 6 Weak entities

7. ISA-hierarchy

8. 8 Cardinality & optionality ( 0,n) (1,1) optional mandatory

9. ERD -> relational schema

10. Solution 1 E1 (K1, A1, …, Am, K2) E2 (K2, B1, …, Bn) Solution 2 E1 (K1, A1, …, Am) E2 (K2, B1, …, Bn, K1)

11. ERD -> relational schema Solution 3 E1 (K1, A1, …, Am, K2) E2 (K2, B1, …, Bn, K1)

12. ERD -> relational schema Solution 4 E1 (K1, A1, …, Am) E2 (K2, B1, …, Bn) R (K1, K2)