Database Test 3 Computer Subject
Database Test 3 Computer Subject
Question 1
In an E-R diagram rectangle with rounded corners represents _______?
In an ER diagram, a rectangle with rounded corners represents a weak entity, which depends on a strong entity for identification.
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Question 2
Relationships among entities of a single class are called _______?
Recursive relationships occur when entities of the same class are related to one another.
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Question 3
In an E-R diagram a relationship is represented by ________?
Relationships in an ER diagram are represented by diamonds connecting entities.
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Question 4
An attribute which consists of a group of attributes is called ______?
Multi-valued attributes can hold multiple values for a single entity instance.
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Question 5
Identifiers that consists of two or more attributes are called _______?
Composite identifiers combine two or more attributes to uniquely identify an entity instance.
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Question 6
Which refers to connecting entities of different types when identifiers are different?
HAS-A relationships connect entities of different types where identifiers differ.
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Question 7
In an E-R diagram an ellipse represents ________?
Ellipses in ER diagrams represent attributes of entities or relationships.
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Question 8
A meaningful association between entity types is _______?
A relationship type defines a meaningful connection between two or more entity types.
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Question 9
Which is not an example of a strong entity type?
A strong entity must be independently identifiable; Student_Id is an attribute, not a strong entity type.
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Question 10
If employee is the entity type, then Michael, Smith is the entity _______?
An instance is a single occurrence of an entity type, e.g., Michael Smith is an instance of Employee.