I am trying my hands on JPA. For this I am thinking of using the example of a student admission process as shown in the diagram below.
Is this design good ?
Any suggestions for improvement are more than welcome.
I am also confused about what Entity classes should I create for this.
Especially for College_Major, should there be an Entity class for this or it should only be a mapping table created for many-to-many mapping between College and Major?
If the latter is a better case, how can the Admission_Form table refer to a Major in a College?
In either case, what should Entity classes (if good to have) for College_Major and Admission_Form look like?
1
Looks a fairly solid design apart from the college_major area which seems to be giving you problems as well 🙂
Personally, I would split this table into two:
- Change the College_Major table to be a true many to many resolver (i.e. no intake int). This would become a reference table which is only changed when a college establishes a new major.
- Intake, which links to College_Major and has the 1:* relationship to admission. I suspect that the intake date should be added, since it should not be possible to enrol a student for a non-existing course.
I like your use of id fields (aka business neutral primary keys). For consistency, the Student table primary key should probably be named student_id rather than just id.
You might like to give some thought to the name Admission_Form. It looks like the database is recording a successful admission, which may not always come from a form, and some forms may never result in an admission.
You will need a an entity class for each table except possibly College_Major. If I remember correctly, Hibernate can handle many to many relationship using collections (e.g College will have a list of majors, and major will have a list of colleges).