Study your flashcards anywhere!

Download the official Cram app for free >

  • Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off
Reading...
Front

How to study your flashcards.

Right/Left arrow keys: Navigate between flashcards.right arrow keyleft arrow key

Up/Down arrow keys: Flip the card between the front and back.down keyup key

H key: Show hint (3rd side).h key

A key: Read text to speech.a key

image

Play button

image

Play button

image

Progress

1/20

Click to flip

20 Cards in this Set

  • Front
  • Back
Subtype entities may be either exclusive or inclusive.
True
The E-R Model assumes that all instances of a given entity class have the same
attributes.
True
If one instance of ENTITY B must be related to one and only one instance of ENTITY
A, and one instance of ENTITY A may be related to many instances of ENTITY B,
which of the following should be written in the relationship symbol of the figure below?
1:N
If one instance of ENTITY B must be related to one and only one instance of ENTITY
A, and one instance of ENTITY A may be related to many instances of ENTITY B,
which of the following should be written in the relationship symbol of the figure below?
1:N
In crow's foot E-R notation, a circle indicates a minimum cardinality of zero.
True
A dashed line between entities indicates:
a nonidentifying relationship.
In crow's foot style E-R diagrams, a crow's foot mark on the relationship line near an
entity indicates:
a maximum cardinality of many.
Maximum cardinality indicates whether or not an instance of one entity class must be
related to at least one instance of another entity class.
False
The number of entity classes involved in a relationship is known as the relationship's:
degree
During the design phase of developing a database system, the users are asked about the
need for changes to existing forms and reports.
True
The PRODUCT entity instance is the collection of all PRODUCT entity classes.
False
The number of entity classes involved in a relationship is the cardinality of the
relationship.
False
It is possible for an entity to have a relationship to itself.
True
During the design phase of developing a database system, the data model is
transformed into a database design.
True
Use cases can be used to validate the data model, design, and implementation.
True
Given only the excerpt of an E-R model shown in the figure below, which of the following is known to be true?
A single instance of ENTITY B may be related to many
instances of ENTITY A.
Which of the following is not a basic element of the E-R Model?
Use cases
In crow's foot style E-R diagrams, a single entity together with a related set of entities
that each contain specific sets of attributes related to the single entity represent:
a supertype / subtype relationship
An ID-dependent entity is:
Both a special type of weak entity and an entity in which the
identifier of the entity includes the identifier of another entity
Whether or not an instance of one entity class must participate in a relationship with
another entity class is indicated by the:
minimum cardinality.