Databases Reference
In-Depth Information
Given names
Surname
Student ID
Date of birth
Year enrolled
Student
Grade: Computing Mathematics
Grade: Programming
Grade: Web Database Appplications
...Attributes for other courses...
Grade: Computer Forensics
Figure 4-5. The ER diagram representation of student grades as attributes of the student entity
Given names
Student
Surname
Year
M
Student ID
Ta ke s
Semester
N
Date of birth
Mark
Year enrolled
Course
Course name
Figure 4-6. The ER diagram representation of student grades as a separate entity
requirements so that the design can be checked against the requirements. All else being
equal, try to keep the design simple, and avoid introducing trivial entities where pos-
sible; i.e., there's no need to have a separate entity for the student's enrollment when
we can model it as a relationship between the existing student and program entities.
