18 Questions
What is the primary key?
Candidate key
Which constraint requires that critical information isn't duplicated?
Candidate key
What is a composite key made up of?
Two or more attributes
Which type of key is used to reference a primary key in another table?
Foreign key
In the context of relational databases, what does 'degree' refer to?
The number of attributes in a relation
What does 'cardinality' signify in relational databases?
The number of tuples in a relation
What does the hierarchical data model prevent entities from doing?
Being related to any entity more than one level up the hierarchy
In the network data model, what is a key feature regarding child entities?
They can have more than one parent
How are entities described in data modeling?
Using a minimal set of attributes that uniquely identify them
What do data model constraints primarily help to ensure?
Data accuracy
Which type of relationship in data models describes an association among two entities?
One-to-one (1:1)
Why are constraints considered important in database design?
To ensure data integrity and consistency
Which type of attribute can be divided into further parts?
Composite attributes
What does a multivalued attribute represent within the ERD symbols?
Attribute
What is the main characteristic of a single-valued attribute?
Cannot be divided further
In an Entity-Relationship Diagram (ERD), what do 'Null Values' represent?
Values that are not applicable or unknown
Which symbol in an ERD represents a multivalued attribute?
( )
What defines the Degree of Relationship in an ERD?
Number of entities participating in the relationship
Test your knowledge on different types of data models including Hierarchical, Network, and Relational. Learn about the key characteristics and differences between these models.
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