Specify an appropriate set of classes for the Student Registration System. Do this using ?rst UDTs of SQL:2003 and then the ODL language of ODMG.

What will be an ideal response?

We modify the tables de?ned in Section 4.8 in two ways: Using references to types instead of foreign key constraints and by making use of set-valued attributes.



CREATE TYPE Course AS (

      CrsCode CHAR(6),

      DeptId CHAR(4) NOT NULL,

      CrsName CHAR(20) NOT NULL,

      creditHours INTEGER NOT NULL,

      SemestersOffered CHAR(6) MULTISET,

      Requires REF(Course) MULTISET,

      PRIMARY KEY (CrsCode)

)



CREATE TYPE Class UNDER Course AS (

      CrsCode CHAR(6),

      SectionNo INTEGER,

      Semester CHAR(6),

      Year INTEGER,

      ClassTime CHAR(6),

      Enrollment INTEGER,

      MaxEnrollment INTEGER,

      Textbook CHAR(50),

      TaughtIn REF(Room),

      Instructor REF(Facu lty ),

      PRIMARY KEY (CrsCode, SectionNo, Semester, Year)

)



CREATE TYPE Room AS (

      ClassroomId INTEGER,

      Seats INTEGER,

      PRIMARY KEY(ClassroomId)

)



CREATE TYPE Student AS (

      Id CHAR(9),

      Address CHAR(50),

      Name CHAR(20),

      Password CHAR(10),

      Transcript REF(TranscriptRecord) MULTISET,

      PRIMARY KEY(Id)

)



CREATE TYPE TranscriptRecord AS (

      Grade CHAR(1),

      Class REF(Class)

)



CREATE TYPE Facu lty AS (

       Id CHAR(9),

       Name CHAR(20),

       Address CHAR(50),

       DeptId CHAR(4),

       Password CHAR(10),

       PRIMARY KEY(Id)

)

The ODMG version of the Student Registration Schema is as follows:



class Course

       (extent CourseExt

        keys CrsCode)

{

       attribute String CrsCode;

       attribute String DeptId;

       attribute String CrsName;

       attribute Integer creditHours;

       attribute Set SemestersOffered;

       relationship Set Requires;

}

class Class extends Course

       (extent ClassExt

         keys (CrsCode, SectionNo, Semester, Year))

{

       attribute String CrsCode;

       attribute Integer SectionNo;

       attribute String Semester;

       attribute Integer Year;

       attribute String ClassTime;

       attribute Integer Enrollment;

       attribute Integer MaxEnrollment;

       attribute String Textbook;

       relationship Room TaughtIn;

       relationship Facu lty Instructor;

}



class Room

       (extent RoomExt

        keys ClassroomId)

{

       attribute Integer ClassroomId;

       attribute Integer Seats;

}

class Student

       (extent StudentExt

         keys Id)

{

       attribute String Id;

       attribute String Address;

       attribute String Name;

       attribute String Password;

       relationship Set Transcript;

}



class TranscriptRecord

       (extent TranscriptRecordExt)

{

       attribute String Grade;

       relationship Class Class;

}



class Faculty

       (extent ProfessorExt

        keys Id)

{

       attribute String Id;

       attribute String Name;

       attribute String Address;

       attribute String DeptId;

       attribute String Password;

}