Chapter 5 Flashcards
Conceptual Model
Is a representation that depicts the important objects and relationships between the objects that must be captured in a databse
Unified Modeling Language (UML)
A widely accepted notation for system analysis and design that includes several types of diagrams for different levels of analysis
Entity
Real world object that has separate existence (either physical or conceptual)
Association
Relationship between classes
Association Class
Represents a relationship in which there can be only one link between the related entities
Attribute
A characteristic possessed by a class or an association
Primary Key Attribute
Used to uniquely and universally describe each instance of a class or association class
Simple Attribute
Attribute that cannot be further decomposed
Composite (Complex) Attribute
May be decomposed into other attributes
Derivable Attribute
Attribute that can be derived (computed) from the values of other attributes in the database.
Static Derivable Attribute
Those for which the derived value will not change if new data is entered into the database
Volatile Derivable Attribute
Those for which the derived value will change if new data is entered into the database
Optional Participation
Means that any specific instance of the class can exist in the database without a corresponding instance of the associated class.
Mandatory Participation
Means that each instance of the class must be related to at least one instance of the associated class in order to be included in the database.
Maximum Multiplicities
Represent the maximum number of times each instance of a class may participate in an association with another class. (one and many)
Foreign Key
The primary key of one class table that is “posted” into another class table to represent an association between those classes.
Referential Integrity
A value for a foreign key attribute must either by null or it must match one of the data values in the table in which the attribute is a primary key
Which statement accurately interprets one or more of the multiplicities that are depicted below in the Alpha to Omega relationship?
Alpha to Omega
0..1 0..*
IDK
Primary key attributes:
IDK
Which statement accurately explains one or more of the following multiplicities between the “Customer Order” and the “Delivery” events?
Customer Order Delivery
1..* 0..1
IDK
Customers that come in to Furniture Galore, Inc. may be helped by any available salesperson. If more than one salesperson helps the same customer with the same merchandise, any resulting sale to that customer will be credited to all involved salespeople, who will split the sale commission. Salespeople are added to the database as soon as they are hired. A sale cannot be made without a salesperson. The multiplicities for the association between the Sale and Salesperson for Furniture Galore, Inc. are:
IDK
Any attribute that may be decomposed into other attributes is called a
IDK
Which of the following represent invalid multiplicities for a class’ participation in an association?
IDK
Which of the following minimum and maximum multiplicities represent a class that has optional participation in an association and can participate in the association multiple times?
IDK
