Refer to the following ERD, which maps courses to prerequisites. answer question
ID: 3886095 • Letter: R
Question
Refer to the following ERD, which maps courses to prerequisites. answer questions
(T || F) _____PREREQ is a weak entity.
(T || F) _____The relationship COURSE:PREREQ is weak.
(T || F) _____All prerequisite courses (crs_code) in PREREQ, must link with a valid course in COURSE.
(T || F) _____The foreign key in PREREQ is a composite key (CRS_ID, PREREQ_ID).
(T || F) _____Upon implementation, table indexes are automatically generated for both tables.
What does it mean to say that a database displays both entity integrity and referential integrity? How are each established?
Explanation / Answer
PREREQ is a weak entity - True
The relationship COURSE:PREREQ is weak - True
All prerequisite courses (crs_code) in PREREQ, must link with a valid course in COURSE - False
The foreign key in PREREQ is a composite key - True
Upon implementation, table indexes are automatically generated for both tables - True
What does it mean to say that a database displays both entity integrity and referential integrity? How are each established?
It means when data is displayed in all fields.