E-R diagrams can be used for designing class de?nitions for object databases. Design ODMG class de?nitions for the E-R diagrams in Figure 4.1, Figure 4.6, and Figure 4.36.
What will be an ideal response?
// For Figure 4.1
class Person : Object
(extent PersonExt
keys SSN)
{
attribute Integer SSN;
attribute String Name;
attribute String Address;
attribute SetHobbies
}
// For Figure 4.6
class Person : Object
(extent PersonExt
keys SSN)
{
attribute Integer SSN;
attribute String Name;
attribute Date DOB;
}
class Employee extends Person
(extent EmployeeExt)
{
attribute String Department;
attribute Float Salary;
}
class Student extends Person
(extent StudentExt)
{
attribute Date StartDate;
attribute Float GPA;
}
class Secretary extends Employee
(extent SecretaryExt)
{
}
class Technician extends Employee
(extent TechnicianExt)
{
attribute String Specialization;
}
class Freshman extends Student
(extent FreshmanExt)
{
}
class Sophomore extends Student
(extent SophomoreExt)
{
attribute String Major;
}
class Junior extends Student
(extent JuniorExt)
{
attribute String Major;
}
class Senior extends Student
(extent SeniorExt)
{
attribute String Major;
relationship Employee Advisor;
}
// For Figure 4.36
class Semester : Object
(extent SemesterExt)
{
attribute Integer Enrollment;
relationship SetHolidays;
}
class Course : Object
(extent CourseExt)
{
... ... ...
}
struct TranscriptRecord
{
String Grade;
Semester Semester;
Course Course;
}
class Student extends Person
(extent StudentExt)
{
attribute SetEnrolled;
}
Computer Science & Information Technology
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