database normalization case study
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The document describes a grade entry system for a high school that allows faculty to store, compute, and record student grades. It includes entity relationship diagrams and descriptions of the key system components, including normalized data schemas and physical database design. The system provides a way to efficiently generate student report cards and grading sheets at the end of each period.
database normalization case study
- 1. CS 507 GRADE ENTRY SYSTEM (GES) For Mahardika Institute of Technology Junior High School Department Prepared by: Mr. Abubakar Hiyang Mr. Gilbert Flores Ms. Claire Ong Mr. Armando So III
- 2. The Grade Entry System of the Mahardika Institute of Technology, Inc. High school Department to help school faculty in storing, computing and recording of grades of the students. The System has the following functions: • Provide a database for recording and grading report • Speed up the generation of student grades •Systematize the recording of grades information INTRODUCTION
- 6. STUDINFO Field Type ID (PK) AutoNumber StudID String FullName String LastName String FirstName String MiddleName String Grade Number Sec String GRADE Field Type ID (PK) AutoNumber SchoolYear (FK) Number Grading Number Grade Number Sec String Subject (FK) Number Teacher (FK) Number Name String Gr Number Gd String StudID Number SCHOOLYEAR Field Type ID (PK) Number SchoolYear String SUBJECT Field Type ID (PK) Number SUBJECT String TEACHER Field Type ID (PK) Number Teacher String USER Field Type UserID (PK) Number LastName String FirstName String MiddleName String Designation String UserName String Password String GES Physical Design
- 7. Architecture • Database is stored in a single MS Access file. • Database is stored on a single computer on a LAN and shared peer-to-peer to other users. • Administrator manages student info, sections, teachers, and subjects. • Teachers manage grades of students. • At the end of each period, the adviser can produce grading reports of his/her class .
- 8. GES VIEWS AND REPORTS
- 9. Login Screen
- 15. Certificate of Grades Report
- 16. Report Card
- 17. GES SCHEMAS AND FUNCTIONAL DEPENDENCIES
- 18. SUBJECT SUBJECT(ID, Subject) ID Subject SCHOOLYEAR SCHOOLYEAR (ID, SchoolYear) ID SchoolYear TEACHER TEACHER (ID, Teacher) ID Teacher
- 19. STUDINFO STUDINFO (ID, StudID, FullName,LastName, FirstName, MiddleName, Grade, Sec, SchoolYear) ID StudID, FullName StudID ID, FullName ID, SchoolYear StudID, FullName, Grade, Sec FirstName, MiddleName, LastName FullName
- 20. Candidate key: ID SchoolYear Non-Primary Keys: Grade, Sec Grade and Sec both are only partially functional dependent to the candidate key, therefore the relation cannot be in 2NF. Only satisfies 1NF. STUDINFO (ID, StudID, FullName,LastName, FirstName, MiddleName, Grade, Sec, SchoolYear) ID StudID, FullName, FirstName, MiddleName, LastName ID, SchoolYear StudID, FullName, LastName, FirstName, MiddleName, Grade, Sec
- 21. Anomalies in STUDINFO Relation: • Anomaly #1: Redundant Attributes FullName is composite having combined values of FirstName, MiddleName and LastName. Fix: Remove redundant attributes FirstName, MiddleName and LastName. STUDINFO (ID, StudID, FullName, Grade, Sec, SchoolYear) • Anomaly #2: Insertion anomaly Adding new SchoolYear will duplicate values of other attributes like StudID and FullName. Fix: Split STUDINFO. STUDINFO (ID, StudID, FullName, Grade, Sec) MASTERLIST (SchoolYear, StudID, SecID) • Anomaly #3: Insertion anomaly Adding new Sec for each student will duplicate values of other attributes. Sec and Grade has no functional dependency in new STUDINFO relation. Fix: Split STUDINFO STUDINFO (ID, StudID, FullName) - 3NF SECTIONS (SecID, Grade, Sec) – 3NF
- 22. GRADES GRADE (ID, SchoolYear, Grading, Grade, Sec, Subject, Teacher, Name, Gr, Gd, StudID) ID SchoolYear, Grading, Grade, Subject, Teacher, Name, Gr, Gd, StudID StudID Name SchoolYear, Grading, Subject, StudID Gr, Gd, Teacher StudID, SchoolYear Grade, Sec StudID, Grade, Sec SchoolYear SchoolYear, Grading, Sec, Subject Teacher Teacher, SchoolYear, Grading Subject
- 23. Anomalies in GRADE Relation: • Anomaly #1: Redundant Attributes Extra attributes from StudInfo used in Grade relation are redundant, since StudID is already a primary key in StudInfo. Fix: Remove redundant attributes. GRADE (ID, SchoolYear, Grading, Subject, Teacher, Gr, Gd, StudID) • Anomaly #2: Inefficient data type for Grading / Update anomaly The Grading attribute uses string values. Fix: Split and modify GRADE relation. GRADE (ID, Period, Subject, Teacher, Gr, Gd, StudID) PERIOD (PeriodID, GradingPeriod) • Anomaly #3: Redundant primary key Fix: Replace the single attribute ID as primary key and just use StudID, SchoolYear and Period as composite key. GRADE (SchoolYear, StudID, Period, Subject, Teacher, Gr, Gd) PERIOD (PeriodID, GradingPeriod)
- 24. USER USER (UserID, LastName, FirstName, MiddleName, Designation, UserName, Password) UserID LastName, FirstName, MIddleName, Designation, UserName, Password UserName UserID, LastName, FirstName, MiddleName, Designation, Password
- 25. Anomalies in USER Relation: • Anomaly #1: Inefficient data type for Designation/ Update anomaly The Designation attribute uses string values. Fix: Split and modify USER relation. USER (UserID, LastName, FirstName, MiddleName, DesignationID, UserName, Password) DESIGNATIONS (DesignationID, Designation)
- 26. GES Modified Relation Schemas STUDINFO (ID, StudID, FullName) SECTIONS (SecID, Grade, Sec) MASTERLIST (SchoolYear, StudID, SecID) SUBJECT(ID, Subject) SCHOOLYEAR (ID, SchoolYear) TEACHER (ID, Teacher) GRADE (SchoolYear, StudID, Period, Subject, Teacher, Gr, Gd) PERIOD (PeriodID, GradingPeriod) USER (UserID, LastName, FirstName, MiddleName, DesignationID, UserName, Password) DESIGNATIONS (DesignationID, Designation)
- 27. STUDINFO ID (PK) StudID FullName SECTIONS SecID (PK) Grade Sec MASTERLIST SchoolYear (FK) StudID (FK) SecID SUBJECT ID (PK) SUBJECT SCHOOLYEAR ID (PK) SchoolYear TEACHER ID (PK) Teacher GRADE SchoolYear (FK) StudID (FK) Period (FK) Subject (FK) Teacher (FK) Gr Gd PERIOD PeriodID (PK) GradingPeriod USER UserID (PK) LastName FirstName MiddlleName DesignationID (FK) UserName Password DESIGNATIONS DesignationID (PK) Designation GES Modified ERD Enrolled in Obtains Submitted by Assigned to Prepared for Submitted for Obtained during Grouped by Designates
- 28. GES Modified Physical Design STUDINFO Field Type ID (PK) AutoNumber StudID String FullName String SECTIONS Field Type SecID (PK) AutoNumber Grade Number Sec String MASTERLIST Field Type SchoolYear (FK) Number StudID (FK) Number SecID Number SUBJECT Field Type ID (PK) Number SUBJECT String SCHOOLYEAR Field Type ID (PK) Number SchoolYear String TEACHER Field Type ID (PK) Number Teacher String GRADE Field Type SchoolYear (FK) Number StudID (FK) Number Period (FK) Number Subject (FK) Number Teacher (FK) Number Gr Number Gd String PERIOD Field Type PeriodID (PK) Number GradingPeriod String USER Field Type UserID (PK) Number LastName String FirstName String MiddlleName String DesignationID (FK) Number UserName String Password String DESIGNATIONS Field Type DesignationID (PK) Autonumber Designation String