input: Write a function to create an application using Python and Flask that allows users to submit form data containing Name, Email, and Phone, and store this data in a SQLite database. The application should have a home route that renders an index.html template and a submit route that handles the form submission and stores the data in the database.
  assert submit_form('John Doe', 'john@example.com', '1234567890')==None
  assert submit_form('Jane Smith', 'jane@example.com', '0987654321')==None
  assert submit_form('', 'invalid@example.com', '1122334455')==None
  assert submit_form('Alice Johnson', '', '5555555555')==None
  assert submit_form('Bob Brown', 'bob@example.com', '')==None
output: def submit_form(name, email, phone):
      from flask import Flask, request, render_template
      import sqlite3
  
      app = Flask(__name__)
  
      def create_table():
          conn = sqlite3.connect('form_data.db')
          cursor = conn.cursor()
          cursor.execute('''
              CREATE TABLE IF NOT EXISTS submissions (
                  id INTEGER PRIMARY KEY AUTOINCREMENT,
                  name TEXT NOT NULL,
                  email TEXT NOT NULL,
                  phone TEXT NOT NULL
              )
          ''')
          conn.commit()
          conn.close()
  
      create_table()
  
      @app.route('/')
      def home():
          return render_template('index.html')
  
      @app.route('/submit', methods=['POST'])
      def submit():
          name = request.form['name']
          email = request.form['email']
          phone = request.form['phone']
          
          conn = sqlite3.connect('form_data.db')
          cursor = conn.cursor()
          cursor.execute('''
              INSERT INTO submissions (name, email, phone)
              VALUES (?, ?, ?)
          ''', (name, email, phone))
          conn.commit()
          conn.close()
          
          return '', 204
  
      with app.test_request_context('/submit', method='POST', data={'name': name, 'email': email, 'phone': phone}):
          submit()