1. Jozef Kuper

2.  Describe a Database  Entities  Atributes  Relationships

3.  Physical object, concept or event  Entity represent table  Attributes represent collums  Primary key

4.  Represented as a lines between entities  May be labeled  Don’t show single instance of relations  Entity sets  Relationships sets  Optional relationship  Mandatory relationship

5.  One-to-one  One-to-many  Many-to-many

6.  Conceptual data model  Useful to support documenting the data architecture  Logical data model  Physical model

7.  Unusual  Used in large tables  Safety

8.  Most used  Relationship 1:N | N:1  Primary key / Foreign key  Classifications

9.  Can not be implemented  Generated associated entity  Combination of entity and relationship

10.  Some entity participates more than once in the relationship  Some common attributes  reports to (manager)

11.  Identify the entity  Identify the entity’s attribute  Identify Primary Keys  Identify relations between entities  Identify the Cardinality constraint

13. Questions Questions?