database.py

import sqlite3

# Create and initialize the database
def initialize_database():
    conn = sqlite3.connect("college.db")
    cursor = conn.cursor()

    # Create student table
    cursor.execute("""
    CREATE TABLE IF NOT EXISTS student (
        student_id INTEGER PRIMARY KEY,
        first_name TEXT,
        last_name TEXT,
        date_of_birth DATE,
        email TEXT,
        phone_number TEXT,
        major TEXT,
        year_of_enrollment INTEGER
    );
    """)

    # Create employee table
    cursor.execute("""
    CREATE TABLE IF NOT EXISTS employee (
        employee_id INTEGER PRIMARY KEY,
        first_name TEXT,
        last_name TEXT,
        email TEXT,
        department TEXT,
        position TEXT,
        salary REAL,
        date_of_joining DATE
    );
    """)

    # Create course table
    cursor.execute("""
    CREATE TABLE IF NOT EXISTS course (
        course_id INTEGER PRIMARY KEY,
        course_name TEXT,
        course_code TEXT,
        instructor_id INTEGER,
        department TEXT,
        credits INTEGER,
        semester TEXT,
        FOREIGN KEY (instructor_id) REFERENCES employee(employee_id)
    );
    """)

    # Clear old data (order matters to avoid foreign key errors)
    cursor.execute("DELETE FROM course;")
    cursor.execute("DELETE FROM student;")
    cursor.execute("DELETE FROM employee;")

    # Insert sample data into student table
    students = [
        (1, "Alice", "Johnson", "2001-06-15", "alice@example.com", "1234567890", "Computer Science", 2019),
        (2, "Bob", "Smith", "2000-04-22", "bob@example.com", "0987654321", "Mechanical Engineering", 2018),
        (3, "Charlie", "Brown", "2002-01-10", "charlie@example.com", "1112223333", "ECE", 2020),
        (4, "Daisy", "Miller", "2001-12-12", "daisy@example.com", "2223334444", "Civil", 2019),
        (5, "Ethan", "Lee", "2000-05-05", "ethan@example.com", "3334445555", "IT", 2018),
        (6, "Fiona", "Clark", "2001-07-07", "fiona@example.com", "4445556666", "CSE", 2020),
        (7, "George", "Adams", "2002-02-02", "george@example.com", "5556667777", "CSE", 2021),
        (8, "Hannah", "Moore", "2001-11-11", "hannah@example.com", "6667778888", "AI", 2019),
        (9, "Ivan", "Davis", "1999-09-09", "ivan@example.com", "7778889999", "ECE", 2017),
        (10, "Julia", "King", "2002-03-03", "julia@example.com", "8889990000", "IT", 2020)
    ]
    cursor.executemany("INSERT INTO student VALUES (?, ?, ?, ?, ?, ?, ?, ?);", students)

    # Insert sample data into employee table
    employees = [
        (1, "Drake", "Miller", "drake@example.com", "CSE", "Professor", 75000.00, "2015-08-01"),
        (2, "Laura", "White", "laura@example.com", "ECE", "Assistant Professor", 65000.00, "2018-07-10"),
        (3, "James", "Hall", "james@example.com", "IT", "Lecturer", 55000.00, "2019-01-15"),
        (4, "Nancy", "Allen", "nancy@example.com", "Civil", "Professor", 80000.00, "2014-06-12"),
        (5, "Oscar", "Wright", "oscar@example.com", "Mechanical", "Assistant Professor", 60000.00, "2016-10-01"),
        (6, "Rachel", "Baker", "rachel@example.com", "AI", "Lecturer", 52000.00, "2020-03-05"),
        (7, "Steve", "Lopez", "steve@example.com", "CSE", "Professor", 78000.00, "2012-08-20"),
        (8, "Tina", "Hill", "tina@example.com", "ECE", "Lecturer", 53000.00, "2017-09-18"),
        (9, "Uma", "Scott", "uma@example.com", "IT", "Professor", 72000.00, "2013-04-07"),
        (10, "Victor", "Green", "victor@example.com", "CSE", "Assistant Professor", 60000.00, "2018-11-23")
    ]
    cursor.executemany("INSERT INTO employee VALUES (?, ?, ?, ?, ?, ?, ?, ?);", employees)

    # Insert sample data into course table
    courses = [
        (1, "Database Systems", "CS301", 1, "CSE", 4, "Fall"),
        (2, "Digital Electronics", "EC202", 2, "ECE", 3, "Spring"),
        (3, "Operating Systems", "CS302", 1, "CSE", 4, "Fall"),
        (4, "Data Structures", "CS201", 10, "CSE", 4, "Spring"),
        (5, "Microprocessors", "EC303", 8, "ECE", 3, "Fall"),
        (6, "Civil Engineering Basics", "CV101", 4, "Civil", 3, "Spring"),
        (7, "Thermodynamics", "ME201", 5, "Mechanical", 4, "Fall"),
        (8, "AI Fundamentals", "AI101", 6, "AI", 3, "Fall"),
        (9, "Web Technologies", "IT301", 3, "IT", 4, "Spring"),
        (10, "Software Engineering", "CS303", 7, "CSE", 4, "Fall")
    ]
    cursor.executemany("INSERT INTO course VALUES (?, ?, ?, ?, ?, ?, ?);", courses)

    conn.commit()
    conn.close()

# Function to execute SQL query and return results
def run_sql_query(sql_query):
    try:
        conn = sqlite3.connect("college.db")
        cursor = conn.cursor()
        cursor.execute(sql_query)
        rows = cursor.fetchall()
        column_names = [description[0] for description in cursor.description] if cursor.description else []
        conn.commit()
        conn.close()

        if not rows:
            return "No rows returned."

        result = "\t".join(column_names) + "\n"
        for row in rows:
            result += "\t".join(str(cell) for cell in row) + "\n"
        return result.strip()
    except Exception as e:
        return f"Error executing query: {e}"

# Run only if this script is the main entry point
if __name__ == "__main__":
    initialize_database()