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():
      """
      This function handles the form submission and stores the form data in a SQLite database.
      It takes the values of 'name', 'email', and 'phone' from the form, inserts them into the 'data' table,
      and then redirects the user back to the home page.
      
      Example:
      >>> from werkzeug.test import EnvironBuilder
      >>> from werkzeug.wrappers import Request
      >>> from flask import Flask, render_template, request, redirect
      >>> import sqlite3
      >>> app = Flask(__name__)
      >>> @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('test.db')
      ...     cur = conn.cursor()
      ...     cur.execute("CREATE TABLE IF NOT EXISTS data (name TEXT, email TEXT, phone TEXT)")
      ...     cur.execute("INSERT INTO data (name, email, phone) VALUES (?, ?, ?)", (name, email, phone))
      ...     conn.commit()
      ...     cur.execute("SELECT * FROM data WHERE email=?", (email,))
      ...     entry = cur.fetchone()
      ...     conn.close()
      ...     return redirect('/')
      >>> builder = EnvironBuilder(method='POST', data={'name': 'John Doe', 'email': 'john@example.com', 'phone': '1234567890'})
      >>> env = builder.get_environ()
      >>> req = Request(env)
      >>> with app.test_request_context(req):
      ...     app.preprocess_request()
      ...     submit()
      >>> conn = sqlite3.connect('test.db')
      >>> cur = conn.cursor()
      >>> cur.execute("SELECT * FROM data WHERE email=?", ('john@example.com',))
      >>> entry = cur.fetchone()
      >>> conn.close()
      >>> entry
      ('John Doe', 'john@example.com', '1234567890')
      """
      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)
  
output:     
      cur.execute("CREATE TABLE IF NOT EXISTS data (name TEXT, email TEXT, phone TEXT)")
      conn.close()
  