Author Question: What are the rules for naming and defining attributes? What will be an ideal ... (Read 70 times)

daltonest1984

  • Hero Member
  • *****
  • Posts: 536
What are the rules for naming and defining attributes?
 
  What will be an ideal response?

Question 2

A ________ is an attribute that appears as a non-primary key attribute in one relation and as a primary key attribute (or part of a primary key) in another relation.
 
  A) Referential integrity
  B) Primary key
  C) Foreign key
  D) Unique key



Sassygurl126

  • Sr. Member
  • ****
  • Posts: 320
Answer to Question 1

Name attributes using the following guidelines:
 An attribute name is a noun.
 An attribute name should be unique.
 To make an attribute name unique and for clarity, each attribute name should follow a standard format.
 Similar attributes of different entity types should use similar but distinguishing names.
 An attribute definition states what the attribute is and possibly why it is important.
 An attribute definition should make it clear what is included and what is not included in the attribute's value.
 Any aliases, or alternative names, for the attribute can be specified in the definition.
 It may also be desirable to state in the definition the source of values for the attribute.
 An attribute definition should indicate if a value for the attribute is required or optional.
 An attribute definition may indicate if a value for the attribute may change once a value is provided and before the entity instance is deleted.
 An attribute definition may also indicate any relationships that attribute has with other attributes.

Answer to Question 2

C



Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
 

Did you know?

Cytomegalovirus affects nearly the same amount of newborns every year as Down syndrome.

Did you know?

The first war in which wide-scale use of anesthetics occurred was the Civil War, and 80% of all wounds were in the extremities.

Did you know?

One way to reduce acid reflux is to lose two or three pounds. Most people lose weight in the belly area first when they increase exercise, meaning that heartburn can be reduced quickly by this method.

Did you know?

Many of the drugs used by neuroscientists are derived from toxic plants and venomous animals (such as snakes, spiders, snails, and puffer fish).

Did you know?

ACTH levels are normally highest in the early morning (between 6 and 8 A.M.) and lowest in the evening (between 6 and 11 P.M.). Therefore, a doctor who suspects abnormal levels looks for low ACTH in the morning and high ACTH in the evening.

For a complete list of videos, visit our video library