is there any noramlization further poosible if so then normalized it
222d ago
Key normalizations made:
- Created a USER table to eliminate redundant user information storage
- Added ASSESSMENT_TYPE table to properly categorize different types of assessments/marks
- Added ATTENDANCE_STATUS table to maintain standardized attendance status values
- Added date field to MARKS table to track when marks were awarded
- Maintained proper relationships with foreign keys
Each table now follows 3NF (Third Normal Form) principles:
- All attributes depend on the primary key (1NF)
- No partial dependencies (2NF)
- No transitive dependencies (3NF)
These changes will:
- Reduce data redundancy
- Improve data integrity
- Make the database more maintainable
- Allow for better data analysis
- Make it easier to modify the system in the future
222d ago
Step 1: First Normal Form (1NF) A table is in 1NF if:
Each column contains atomic (indivisible) values. Each column contains values of a single type. Each row has a unique identifier (Primary Key). Observation:
The given ER diagram already follows 1NF because all attributes contain atomic values. Step 2: Second Normal Form (2NF) A table is in 2NF if:
It is in 1NF. All non-key attributes are fully functionally dependent on the primary key (no partial dependency). Possible Partial Dependency Issues:
SUBJECT Table: The class_id and teacher_id are functionally dependent on the subject, but they introduce partial dependency as a subject can belong to multiple classes and teachers. MARKS Table: The student_id and subject_id form a composite key, but marks depend only on student_id and subject_id together. Solution:
Decompose SUBJECT into two separate tables: SUBJECT(subject_id, subject_name) CLASS_SUBJECT(class_id, subject_id, teacher_id) Decompose MARKS into: MARKS(marks_id, student_id, subject_id, marks) Step 3: Third Normal Form (3NF) A table is in 3NF if:
It is in 2NF. It has no transitive dependencies (i.e., no non-key attribute should depend on another non-key attribute). Possible Transitive Dependency Issues:
STUDENT Table: The class_name in the CLASS table depends on class_id, which is already a primary key. No transitive dependency here. NOTICE Table: The admin_id determines admin_name, email, password, which violates 3NF. Solution:
Remove admin details from NOTICE and create an ADMIN(admin_id, name, email, password) table, which already exists. Final Normalized Tables ADMIN(admin_id, name, email, password) CLASS(class_id, class_name) STUDENT(student_id, name, email, password, class_id) TEACHER(teacher_id, name, email, password) SUBJECT(subject_id, subject_name) CLASS_SUBJECT(class_id, subject_id, teacher_id) MARKS(marks_id, student_id, subject_id, marks) ATTENDANCE(attendance_id, date, student_id, subject_id, status) NOTICE(notice_id, title, description, date, admin_id) COMPLAINT(complaint_id, description, date, student_id) COURSE(course_id, course_title, description, subject_id) Conclusion The ER diagram was already in 1NF. We resolved partial dependencies in 2NF by breaking down SUBJECT and MARKS tables. We removed transitive dependencies in 3NF by ensuring all attributes depend only on the primary key.
Give me downloadable 1nf, 2nf and 3nf er normalized table from the given information
222d ago
Key changes in each normalization step:
1NF:
- All tables have primary keys
- All attributes contain atomic values
- No repeating groups
2NF:
- Separated SUBJECT into SUBJECT and CLASS_SUBJECT tables to remove partial dependencies
- Each non-key attribute is fully dependent on the primary key
3NF:
- Created USER table to eliminate redundant user information
- Added ATTENDANCE_STATUS table to normalize status values
- Added date field to MARKS table
- All non-key attributes are now dependent only on the primary key
- Removed transitive dependencies
These normalized tables will:
- Reduce data redundancy
- Improve data integrity
- Make the database more maintainable
- Allow for better data consistency
- Make it easier to modify the system in the future
You can use these diagrams as a reference for implementing the database structure in your preferred database management system.
222d ago