title: Handle dynamic mapping and inheritance in database schema?
body: <p>I'm developing a nursery school's management system using Hibernate &amp; Struts 2. The core problem lies in the differences of each student within a class (absenceCount, basicStudyFee, fee for each subjects, extra fee...). Each month, the class proposes a standard fee for each normal meal, fee for breakfast (breakfast is optional), basic study fee, fee for each subject (each student could attend zero or all subjects), extra fee (maybe electricity fee, service fee... and each could varies among student). About meal fee (normal meal and breakfast), it depends on the absence days of each student. The students then somehow inherits some of the fees, and ignore some to apply their own rules.</p>
  
  <p><br />However, the schema I designed below does not fully meets the needs of the system, as currently it could only handle the fee applied by the class to all students (without any differences among students) and it somehow contains unclear business logic.   </p>
  
  <p><br /> How should I edit this schema to reflect successfully my business logic (reflect class-applied fee and student-applied fee)?
  <img src="https://i.stack.imgur.com/YhEru.png" alt="enter image description here"></p>