1. Principles Graphical Languages Modeling Constraints
Conceptual Data Model
Principles
Graphical Languages
Modeling
Constraints
Bogdan Shishedjiev Conceptual Data Model

2. Bogdan Shishedjiev Conceptual Data Model
Principles
Main approach – object-oriented
Class (entity set, object)
Association (relationship, relation)
Data member (attribute, property)
Instance (entity, occurrence)
Bogdan Shishedjiev Conceptual Data Model

3. Bogdan Shishedjiev Conceptual Data Model
Languages
Entity Relationship model (E-R) (ERM)
Entity set
Relationship
Attribute
Bogdan Shishedjiev Conceptual Data Model

4. Bogdan Shishedjiev Conceptual Data Model
Languages
MERISE
Object with occurrences
Relation
Propertiy
Bogdan Shishedjiev Conceptual Data Model

5. Bogdan Shishedjiev Conceptual Data Model
Languages
Object Role Modeling (ORM)
                           
Bogdan Shishedjiev Conceptual Data Model

6. Bogdan Shishedjiev Conceptual Data Model
Languages
Class Diagram
Class with instances
Association
Property
Bogdan Shishedjiev Conceptual Data Model

7. Bogdan Shishedjiev Conceptual Data Model
Conceptual Model
Goals
Starting from the dictionary and the rules this model tries to reveal the relations among the data and their interaction
Example – School
Rules
Every class has a one and only one room.
Every subject is teaches by only one teacher.
Every class is taught a subject a fixed number of hours.
Every student can have no more one mark in every subject.
The school manages the timetable and the rating of students and teachers..
Dictionary
Student’s Address,
Subject,
Number of Hours,
Class Name,
Student's Family Name,
Teacher‘s Name,
Mark,
Room Number,
Student’s Name
Bogdan Shishedjiev Conceptual Data Model

8. Bogdan Shishedjiev Conceptual Data Model
Concepts
Class (Entity class, Entity instance)
Association
Relationship between entity instances
Attribute
Properties
Bogdan Shishedjiev Conceptual Data Model

9. Defining an Entity Class
Give it a name (a noun)
Define its attributes
Define the rules
What belongs to the class?
How the instances are identified in the class?
Identifying an instance (Identifier)
First Name
Last Name
Address
STUDENT
Attribute
NAME
Bogdan Shishedjiev Conceptual Data Model

10. Bogdan Shishedjiev Conceptual Data Model
Association
Give a name (a verb)
Determine the participating classes
Define the cardinalities
Bogdan Shishedjiev Conceptual Data Model

11. Bogdan Shishedjiev Conceptual Data Model
Examples
Bogdan Shishedjiev Conceptual Data Model

12. Identifier of an Association
Bogdan Shishedjiev Conceptual Data Model

13. Cardinalities of an Association
Cardinalities One to One
0..1 – 0..1 – Every student can use one locker
0..1 – 1
1 – 1 Every student uses a locker and ther are no free lockers
Bogdan Shishedjiev Conceptual Data Model

14. Cardinalities of an Association
Cardinalities One to Many
1 – 1..N
0..1 – 1..N
1 – 0..N
0..1 – 0..N
Bogdan Shishedjiev Conceptual Data Model

15. Cardinalities of an Association
Cardinalities Many to Many
1..N – 1..N
0..N – 1..N
0..N – 0..N
Bogdan Shishedjiev Conceptual Data Model

16. Cardinalities of an Association
Generalization
Minimal cardinality
Mandatory participation of every instance - 1
Optionally participation of every instance - 0
Maximal cardinality
To only one instance of the other class – 1
To multiple instances of the other class - N
Bogdan Shishedjiev Conceptual Data Model

17. Dimension of an Association
Number of different classes participating in it
Multidimensional
Bogdan Shishedjiev Conceptual Data Model

18. Dimension of an Association
Multidimensional
Bogdan Shishedjiev Conceptual Data Model

19. Dimension of an Association
One-dimensional (Reflexive)
Bogdan Shishedjiev Conceptual Data Model

20. Aggregate Associations
Aggregation
Composition
Bogdan Shishedjiev Conceptual Data Model

21. Bogdan Shishedjiev Conceptual Data Model
Weak Entities
It is identified through the association
Bogdan Shishedjiev Conceptual Data Model

22. Bogdan Shishedjiev Conceptual Data Model
Recommendations
Don’t use high dimension associations
Be aware not replace classes by associations
Bogdan Shishedjiev Conceptual Data Model

23. Case Study – Management Rules
A patient is characterized by:
Unique Number
Name
address
Phone Number
General practitioner is characterized by:
Serial Number
Each patient is supervised by a GP
A policlinic is characterized by:
Address
A specialist is characterized by:
Each specialist has one or more specialties
Each specialist can give consultations in one or more policlinics
Each policlinic groups several specialists
A patient can make an appointment for a consultation with specialist in a given policlinic, The specialist must work in this policlinic
The appointment is for a date that is later than the date of appointment
If the consultation does not take place a new appointment must be made no matter what are reasons for the failure
Lists of appointment for every specialist are made at the beginning of the day.
In the end of every day two reports are made:
A log of appointment made
A log of consultations done
Bogdan Shishedjiev Conceptual Data Model

24. Case Study - Policlinic
Bogdan Shishedjiev Conceptual Data Model

25. Case Study - Policlinic
Bogdan Shishedjiev Conceptual Data Model

26. Bogdan Shishedjiev Conceptual Data Model
Subtypes
Example – Hardware components order
Bogdan Shishedjiev Conceptual Data Model

27. Bogdan Shishedjiev Conceptual Data Model
Subtypes
Bogdan Shishedjiev Conceptual Data Model