input: Write a function that creates an API in Python to fetch data from an SQL database and return the data in JSON format.
  import json 
  import sqlite3
  from flask import Flask, request, jsonify 
  
  app = Flask(__name__) 
    
  def dict_factory(cursor, row):
      d = {}
      for idx, col in enumerate(cursor.description):
          d[col[0]] = row[idx]
      return d 
    
  @app.route('/', methods=['GET'])
  def index(): 
      connection = sqlite3.connect('database.db')
      connection.row_factory = dict_factory
      cur = connection.cursor() 
      all_users = cur.execute('SELECT * FROM users;').fetchall() 
      return jsonify(all_users) 
    
  if __name__ == '__main__': 
      app.run(debug = True)
  
  assert index() == jsonify([{'id': 1, 'name': 'John'}, {'id': 2, 'name': 'Jane'}])
  assert index() == jsonify([{'id': 1, 'name': 'Alice'}, {'id': 2, 'name': 'Bob'}])
  assert index() == jsonify([])
  assert index() == jsonify([{'id': 1, 'name': 'Tom'}, {'id': 2, 'name': 'Jerry'}])
  assert index() == jsonify([{'id': 1, 'name': 'Mike'}, {'id': 2, 'name': 'Sara'}])
output: 
  def index(): 
      connection = sqlite3.connect('database.db')
      connection.row_factory = dict_factory
      cur = connection.cursor() 
      all_users = cur.execute('SELECT * FROM users;').fetchall() 
      return jsonify(all_users)
  