basic concepts of object oriented DBMS

15. Subclasses, Superclasses and inheritance Some objects may have similar but not identical attributes and methods. If there is a large degree of similarity, it would be useful to be able to share the common properties. Inheritance allows one class to be defined as a special case of a more general class. These special cases are known as subclasses and the more general cases are known as superclasses.

17. Example person staff manager SalesStaff Superclasses subclasses Staff is also a subclass Of a superclass person

22. Example staff manager salesstaff salesmanager

26. Method void print() { Printf(“branchno%s”,branchno); Printf(“city %s”,city); Printf(“postcode%s”,postcode); } method void print() { Printf(“staffno%d”,staffno); Printf(“name%s”,name); Printf(“gender%c”,gender); }

28. Staff Staffno Name Position Dob salary Manager Bonus mgrstartdate Salesperson Salesarea carallowance Secretary typingspeed

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