Lesson 10.4: Mini Project 4 – Database Application

Python Programming for Beginners to Advanced

Lesson 10.4: Mini Project 4 – Database Application

Introduction:
This project focuses on creating a Python application that interacts with a database. Students will practice CRUD operations, file handling, and OOP concepts while building a practical system that stores and manages data efficiently.

1. Project Overview:

Features: Add, view, update, and delete records
Uses SQLite (or MySQL for advanced learners)
Menu-driven interface for user interaction
Logs actions for better tracking

2. Step-by-Step Implementation:

Step 1 – Setup Database:

Step 2 – Define CRUD Functions:

def add_student(name, age, grade):

    cursor.execute("INSERT INTO students (name, age, grade) VALUES (?, ?, ?)",

                   (name, age, grade))

    conn.commit()
def view_students():

    cursor.execute("SELECT * FROM students")

    for row in cursor.fetchall():

        print(row)
def update_student(student_id, name, age, grade):

    cursor.execute("UPDATE students SET name=?, age=?, grade=? WHERE id=?",

                   (name, age, grade, student_id))

    conn.commit()

def delete_student(student_id): cursor.execute("DELETE FROM students WHERE id=?", (student_id,)) conn.commit()

Step 3 – Menu Interface:

while True:

    print("\nDatabase Application Menu")

    print("1. View Students")

    print("2. Add Student")

    print("3. Update Student")

    print("4. Delete Student")

    print("5. Exit")
    choice = input("Enter choice (1-5): ")

if choice == "1": view_students() elif choice == "2": name = input("Enter name: ") age = int(input("Enter age: ")) grade = input("Enter grade: ") add_student(name, age, grade) elif choice == "3": student_id = int(input("Enter student ID to update: ")) name = input("Enter new name: ") age = int(input("Enter new age: ")) grade = input("Enter new grade: ") update_student(student_id, name, age, grade) elif choice == "4": student_id = int(input("Enter student ID to delete: ")) delete_student(student_id) elif choice == "5": print("Exiting Database Application...") break else: print("Invalid choice")

3. Practical Tips:

Always close the database connection: conn.close()
Validate user input to prevent errors
Use logging to track database actions for debugging and audit
For advanced learners, consider connecting to MySQL or PostgreSQL

Learning Outcome of This Lesson:

Build a functional Python database application
Perform CRUD operations on SQLite or MySQL
Apply Python OOP and file handling concepts in a project
Gain confidence in building real-world Python applications