Database Reference
In-Depth Information
F
IGURE
2.2
The Schools entity
are stored in the Schools entity. Although this approach consolidates all in-
formation in a single entity, it is not the most flexible solution. Whenever
either a school
or
a dean is updated, the record must be retrieved and up-
dated. Additionally, having a school with no dean (or a dean with no school)
creates a half-empty record. Finally, it creates data retrieval problems.
What if you want to write a report to return information about deans? You
would have to retrieve school data as well. What if you want to track all the
employees who work for the dean? In this case, you would have to relate
the employees to the combined Deans/Schools entity instead of only to
deans. Now consider Figure 2.3.
F
IGURE
2.3
The Schools and Deans entities
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