return response, render_template('database.html')
return render_template('database.html'), response

@app.route('/database')
def database():
    # generate some file name
    # save the file in the `database_reports` folder used below
    return render_template('database.html', filename=stored_file_name)

@app.route('/database_download/<filename>')
def database_download(filename):
    return send_from_directory('database_reports', filename)