student_dbms/README.md

Student Management System

A terminal CRUD application for managing Students, Guardians, and Attendance records, backed by MySQL. Built against the schema in Tables 9.3–9.5 (STUDENT, GUARDIAN, ATTENDANCE).

What it does on startup

1. Connects to the MySQL server at 10.10.0.160:3306.
2. Verifies the student_db database exists — creates it if not.
3. Verifies the GUARDIAN, STUDENT, and ATTENDANCE tables exist (in that order, since STUDENT references GUARDIAN and ATTENDANCE references STUDENT) — creates any that are missing, with the exact data types and constraints from the schema (primary keys, foreign keys, NOT NULL, UNIQUE on GPhone, and the composite primary key (AttendanceDate, RollNumber) on ATTENDANCE).
4. Launches an interactive menu for Create / Read / Update / Delete.

Setup

1. Install the one dependency:

   pip install -r requirements.txt
   

2. Set your MySQL credentials as environment variables (the host/port/ database default to the assignment's values already):

   export DB_USER=root
   export DB_PASSWORD=your_password_here
   # optional overrides — these already default correctly:
   # export DB_HOST=10.10.0.160
   # export DB_PORT=3306
   # export DB_NAME=student_db
   

3. Run it:

   python3 main.py
   

Files

File	Purpose
config.py	Connection settings (reads env vars, falls back to defaults)
db.py	Connects to MySQL; verifies/creates the database and tables
crud.py	All Create/Read/Update/Delete operations for the three tables
ui_helpers.py	Input prompts/validation and table-printing for the terminal
main.py	The menu-driven application — run this

Using the app

The main menu has three sections:

• Guardian management — list, view, add, update, delete guardians. GUID must be a 12-digit number (per the Aadhaar-number schema note); phone, if given, must be 10 digits and is unique across guardians.
• Student management — list, view, add, update, delete students. Roll number is up to 3 digits; each student must reference an existing guardian's GUID (add the guardian first).
• Attendance management — mark attendance (P/A) for a student on a date (marking the same student+date again updates it instead of erroring), view attendance by date or by student, and delete records.

Deleting a guardian who still has students is blocked by the foreign key (delete or reassign their students first). Deleting a student cascades and removes their attendance records automatically.

Notes

• Uses mysql-connector-python, Oracle's official pure-Python MySQL driver — no system libraries (like libmysqlclient) required.
• All input is validated against the schema's constraints (max lengths, digit counts, date format, P/A status) before hitting the database, and database-level errors (duplicate keys, foreign key violations) are caught and shown as friendly messages rather than crashing.
• Tested end-to-end (connect → create DB/tables → full CRUD → constraint error handling → cascade delete) against a local MySQL/MariaDB instance before delivery.