This document discusses the components of an entity-relationship diagram including entities, attributes, relationships, and constraints. An entity-relationship diagram is a conceptual data model that shows entities, attributes, and relationships. The diagram defines entities, attributes, and three types of relationships: one-to-one, one-to-many, and many-to-many. It also covers cardinality and participation constraints that specify the minimum and maximum number of relationships allowed.

1. Entity-Relationship Diagram

2. 
Conceptual Data Model)
E-R

3. 

4. Strong entity
Weak entity
Associative entity*

5. 

6. Single-valued attribute
Multi valued attribute
Derived attribute

11. Simple Attribute
Composite Attribute

12. 

13. Relationship
Identifying Relationship

14. Unary
entity instance
entity type

15. Binary
entity instance 2
entity type

16. Ternary
entity instance 3
entity type

17. 
 Cardinality Constraints
 Participation Constraints

18. 
3

One-to-one relationship

One-to-many relationship

many-to-many relationship

19.  One-to-one relationship
1 1

20.  One-to-many relationship
1 M

21.  many-to-many relationship
M N

22. 
 Total Participation ( )
 Partial Participation ( )
Total Participation Partial Participation
M N

23. 




24. 
Entity Relationship Diagram
Primary key