Case study - relational model
Here is a simple relational model. For example, each exam subject has several papers (left two boxes above). Here is some jargon you may come across: The papers are called 'children' of their subject. .They are in a 'one-to-many' relationship. The subject id in the papers table is called a 'foreign key'.
This takes you to the maths subject.
- Drill downwards into any of the papers by clicking on the three dots in that row.
- You can go back up to Maths subject or
- Go further downwards to results records (you will need to click the 'List' button.because it has not be configured to open automatically).
- From the results page you can go upwards to student, subject or paper.
- From Student you can go back downwards to more results for that student.
In this way you cen navigate around the whole database structure.
If you go to a subject that has papers, you won't be able to delete it. This is to retain the integrity of the data. You have to delete the papers first. This is called 'referential; integrity'.