10 Questions
What is a necessary condition for a weak entity in a database model?
It must participate in an identifying relationship type
How is a weak entity identified in a database model?
By the identifying relationship type it is involved in
In the example given, how is a DEPENDENT entity identified?
By the dependent's first name and the associated EMPLOYEE
What is an identifying entity type in the context of weak entities?
An entity type that determines how a weak entity is uniquely identified
What does the HoursPerWeek attribute of a relationship type like WORKS_ON describe in a database model?
The number of hours one employee works on a specific project per week
How are individual participating entities related in a relationship set?
They are related using straight lines
How is a relationship type represented in an ER diagram?
As a diamond-shaped box
What is the significance of a diamond-shaped box in an ER diagram?
It displays a relationship type
How are the participating entity types connected to the relationship type in an ER diagram?
Via straight lines
What is the difference between an arrow and a straight line in an ER diagram?
An arrow shows directionality, while a straight line simply connects entities
Explore how relationships of the same type are organized into relationship types within a database system. Learn about the significance and implementation of relationship types.
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