Design ( Logical, Physical ). Analysis. Construction. Adjust data model to a database technology (e.g., relational). Business & information needs. Pros & cons. Create data model. Design storage & input/output.
Adjust data model to
Pros & cons.
Specifications for storage & access methods (indexes), and forms & reports
Class diagram (classes & relationships) and write business rules.
List or diagram of normalized tables (schema).
Order(OrderID, EID, CID,
A static model of classes and their relationships
Use case diagram
Shows actors (users) and system functions.
Interactions among objects with a timeline indicated.
The steps within a function (or procedure, use case).
The structure of the code or of the run-time modules.Unified Modeling Language (UML)
Trendy notation for analyzing systems and often used with the
object orientation (OO) approach.
Contains specific sorts of diagrams:
Entity: The aspect of reality recorded in the system.
Class: Description of an entity, which includes its attributes (properties) and behavior (methods, procedures).
Object: One instance of a class with specific data; a record in a database.
Attribute:A data property of a class; an aspects of an entity.
Behavior: Procedures (methods, processes, functions) performed by the class.
Association: A connection between classes or between entities.
Class: Customer, includes attributes and behavior (below)
Object: 12257, Joe Jones... (a specific customer)
Attributes: CustID, Name...
Behavior: AddCustomer, DeleteCustomer... (CRUD)
Association: Class Customer is related to class Order reflecting relationship between entities Customer and Order.
Product Search Profile
NOTE: Assumed way of reading is left-right and top-down.
If the relationship is drawn that way, the arrowhead is not necessary.
Arrowheads needed when these rules are not followed (Figure B).
Degree of Association
Association Degree refers to the number of classes involved in an association:
1) Class with itself – unary (below); rare
2) Between 2 classes – binary (previous slide); most frequent and most important!)
3) Between 3 or more classes – N-ary; rare
Example: many-to-one (M:1) relationship
Multiplicity (Cardinality*) of Associations
An employee must work in only one department, and one (each) department has one or more employees.
classified on it as well.
- examples: Customer—Order, Client—Account
- examples: Order—Item, Student—Course
- example: Customer—BillingAddress, Citizen-- SocaiInsuranceUser (IncomeTaxPayer…)
(Form A question)
One (each) object on the left side of the association is
associated with how many objects on the right side?
2. Write the numbers/asterisks on the right side.
3. Ask the same question from the other side of the relationship:
One (each) object on the right side of the association is associated with how many objects on the left side?
4. Write the numbers/asterisks on the
Note: You need to memorize the multiplicity question!
Procedure for Determining Multiplicity
(Form B question)
1. How many objects on the left side are associated with
one (each) object on the right side?
2. Write the numbers/asterisks of the left side.
3. How many objects on the right side are associated with
one (each) object on the left side?
4. Write the numbers/asterisks on the right side.
Note: We usually need to ask just about maximum multiplicity.
* (many); also labeled as M or N
specific number, if known (3, 10); e.g., in part-whole relationship
.Notation for Multiplicity
NOTE: Some imprecision in Fig. 2.8 p. 49 in 5th ed. (p. 46 4th ed.): “Order” is called “Sale” in sentence two.
and each order is placed by
and only one customer.
2) Each order can contain one or more items,
and an item can be listed on no (0) order or on many orders. *
.Business Rules for Cardinality - Read/Write
Components are assembled into Products by Employees. Simultaneous relationships. Try to read multiplicity.
Support to inventory scheduling, quality control, performance measurement.
But, the data model is not complete as shown!
NOTE: Some imprecision in Fig. 2.9 on p. 49 in 5th ed. (p. 46 in 4th ed.). An association between Employee and Component missing; incorrect way of stating M:M multiplicity.