MIS-430 Quiz 3 Spurrier
Example of aggregation association?
A team in which an entity exists for team, supervisor, and team member. Team is not a permanent structure and the identity of a team member or supervisor is not dependent on the team
What is an Entity Type?
A collection of entity instances that share the same attributes and relationships; typically just referred to as an entity
What is an aggregation association?
A part whole association that can be reconfigured
What is an composition association?
A part-whole association in which parts are entirely dependent on the whole and are assumed to belong to only one whole
Associative entity example
A relationship between sale and product. The AE would be "line item" because a product can be a part of a sale multiple times. We would like to know the quantity and price of each sale which can not be sufficiently represented in a non-associative m:n relationship, thus the line item AE
What is an associative entity?
An entity type that represents a many-to-many relationship between two entity types; typically does not have a unique identifier
What is an entity instance?
An occurrence of an entity type; i.e: Entity Type = Student, Entity Instance = Tristan Collins
The two biggest differences between UML and EER modeling is
Approach and terminology
What is a Binary relationship?
Two entity types in a relationship with each other; most common
What are the 3 degrees of relationships?
Unary, Binary, and Ternary
UML stands for
Unified Modeling Language
When would an associative entity be used?
When a normal many to many relationship between entities is not sufficient
When will behaviors/methods be used?
When you need to express a change in value of a specific attribute. i.e: a grade a student has not gotten yet, students attendance for class not yet happened, name change etc. etc.
When would you want to implement an associative entity with a primary key?
When you need to model multiple instances of the association between the same two instances of the connected entities. I.e: If you had a pricing model in which price changes according to quantity sold, you would want a unique identifier to specify which pricing category they were sold under
Although UML and EER take different approaches, what do they do the same?
Serve the same purpose: modeling the domain of interest
Multiplicity notations:
Chart is figure 3-13 For UML: 0..1 = Optional One 1 = Mandatory 1 0..* = Optional Many 1..* = Mandatory Many * = Many (not recommended because use is vague) n..m = Many with specific lower and upper bounds
EER is typically referred to as ___________ UML is typically referred to as __________
Conceptual Data Modeling Domain Model
When are data/attributes going to be used?
Data/attributes will be used when it does not make sense to specify behaviors or transformations (most cases) and/or when objects will not have behaviors, but simply exist (i.e: insurance claim, sales order, prescription. Things that companies deal with quite often but do not actually do anything)
"Modeling Notations" can also be referred to as
Diagram Grammars
Donda or CLB?
Donda, automatic -60 for CLB
What are the two types of modeling notations (covered in chapter 3)?
EER and UML
EER stands for
Enhanced Entity Relationship
EER modeling takes the ________ approach where as UML modeling takes the ____________ approach
Entity Relationship, Object Oriented
What is an specialization association?
Identifying opportunities to divide instances of an entity type further into subtypes
What is an generalization association?
Identifying similarities and differences between classes of things and organize these classes hierarchically; in terms of coding, extending a class to inherit needed fields
Example of a composition association?
In the line item example, composition occurs because each line item is uniquely associated with a single sale; the line item only exists when a sale is made
Example of a generalization association?
Instead of having a radio ad entity and online ad entity with unique identifiers, you would have an advertisement entity where overlap is identified and radio and online are connected to the supertype (advertisement). Unique fields are then added to radio and online entities (rotation for radio, clicks for online)
Example of a specialization association?
Instead of packing undergrad, grad, and doctorate students into one entity, you would create subtypes for each
Terms for 3-1 table
Not putting that in the quizlet, but just know if you see a term you don't recognize it's probably on this table. Ctrl + F>"3-1"
What is a unary relationship?
One entity type in a relationship with itself
What is a Ternary relationship?
Threesome