In: Computer Science
Consider the following description for a university database system, split into numbered sentences for easy reading:
(i) The university offers several modules, and students can enroll into one or more modules.
(ii) Each module, identified using a unique ID, will involve multiple assignments.
(iii) Each assignment will be allocated a number that is unique within that module (but not necessarily across modules).
Which entity among those in the description is suitable to be modeled as a WEAK ENTITY SET?
A. Assignment
B. Module
C. Students
D. University
The weak entity here will be Assignment and the reason behind that will be that according to the defination of weak entity , it is that entity which cannot be uniquely identified by its attributes alone it needs a foreign key as well in conjunction with its attributes to create a primary key which in our example is clearly visible that assignment cannot be uniquely identified by its allocated number alone it would require its module ID as well because the assignment number is unique in that model only.