import sqlalchemy
from sqlalchemy import create_engine
import pandas as pd

def create_connection(db_name):
    """Create a database connection."""
    engine = create_engine(f'sqlite:///{db_name}.db')
    return engine

def insert_data(engine, table_name, data_frame):
    """Insert data into a specified table."""
    data_frame.to_sql(table_name, con=engine, if_exists='append', index=False)

def fetch_data(engine, query):
    """Fetch data using a SQL query."""
    return pd.read_sql(query, con=engine)