Polymorhism: is a feature of OOPl that at run time depending upon the type of object the appropriate method is called.
Inheritance: is a feature of OOPL that represents the "is a" relationship between different objects(classes). Say in real life a manager is a employee. So in OOPL manger class is inherited from the employee class.
Encapsulation: is a feature of OOPL that is used to hide the information.
Polymorhism: is a feature of one name multiple form.
Inheritance: is a feature of drving sub class from super class.
Encapsulation : is a feature of wrapping the data and function into single unit.
Given two tables Student(SID, Name, Course) and Level(SID, level) write the SQL statement to get the name and SID of the student who are taking course = 3 and at freshman level.