input: 
  from flask import Flask, render_template, request, redirect
  import sqlite3
  
  app = Flask(__name__)
  
  @app.route('/')
  def home():
      return render_template('index.html')
  
  @app.route('/submit', methods=['POST'])
  def submit():
      name = request.form.get('name')
      email = request.form.get('email')
      phone = request.form.get('phone')
      
      conn = sqlite3.connect('data.db')
      cur = conn.cursor()
      
      cur.execute("INSERT INTO data (name, email, phone) VALUES (?, ?, ?)", (name, email, phone))
      conn.commit()
      
      return redirect('/')
  
  if __name__ == '__main__':
      app.run(debug=True)
  
  def store_form_data(form_data: dict) -> bool:
      """Stores the form data submitted via a web form into a SQLite database.
      The form data contains three fields: name, email, and phone.
  
      >>> store_form_data({'name': 'John Doe', 'email': 'john@example.com', 'phone': '123-456-7890'})
      True
      >>> store_form_data({'name': 'Jane Smith', 'email': '', 'phone': '987-654-3210'})
      False
      """
      if not all(key in form_data for key in ['name', 'email', 'phone']):
          return False
  
      name = form_data['name']
      email = form_data['email']
      phone = form_data['phone']
      
      if not (name and email and phone):
          return False
  
      conn = sqlite3.connect('data.db')
      cur = conn.cursor()
      cur.execute("INSERT INTO data (name, email, phone) VALUES (?, ?, ?)", (name, email, phone))
      conn.commit()
      conn.close()
      return True
  
output:     conn = sqlite3.connect('data.db')
      cur = conn.cursor()
      cur.execute("INSERT INTO data (name, email, phone) VALUES (?, ?, ?)", (name, email, phone))
      conn.commit()
      conn.close()
      return True