The document discusses the entity-relationship (E-R) model, which is a high-level conceptual data model introduced by Peter Chen in 1976. The E-R model represents entities, attributes, and relationships. Entity relationship diagrams (ERDs) are used to graphically represent the E-R model. ERDs help in mapping the conceptual data model to logical and physical data models used in database management systems (DBMS). The E-R model defines key concepts like entities, attributes, relationships, relationship sets, and relationship types.

1. LECTURE 3
slide 3

2. Entity – Relationship Model
E-R Model Chen
(1976)
High – level Conceptual Data
Model) DBMS
E-R Model
Entity) ,
Attribute)
Relationship)

3. Entity – Relationship Model
ERD
ERD
DBMS)
Mapping Data Model)

4. Concepetual Data Models
Logical
Data Models
Physical Data Models

5. M
Customer Order
PK Cust_ID
1 M PK Order_ID
Name FK Cust_ID Product
submit 1 M
Address FK Pro_id PK Pro_ID
Tel include
OrderDate ProName
Customer Order
PK Cust_ID Char(5) PK Order_ID Char(5)
1 M
Name Char(30) FK Cust_ID Char(5) Product
Address Char(50) submit
1 M PK Pro_id Char(10)
FK Pro_id Char(10) include
Tel Char(10) ProName Char(30)
OrderDate Date

6. Entity

Entity Type)

7. Entity Instance
Entity Occurrence

 Entity Type) “
Entity
Instance 100

8. E-R
Entity
Attribute
Relationship

9. Attribute)
Attribute)

10. 1. Simple
Attribute Atomic Attribute
2 Composite
Attribute)
3 (Key
Attribute)
4 Single Attribute)
5 Multi-Valued Attribute

11. Simple Attribute
Atomic Attribute

12. (Composite Attribute)

13. Key
Attribute

14. (Single-valued Attribute)
-

15. (Multi-valued Attribute)
-

16. Multi-valued Attribute

17. • Derived Attribute

20. Relationship)

21. Relationship Set)
Entity Type)

22. M
Relationship

23. 1. ER Diagram
(Member)
(
)
(Title)
Muti-Value Attribute)
Category)