Flask, потоки и БД

import sqlite3
import json
from flask import Flask, request
import vk_api
 
app = Flask(__name__)
 
@app.route('/')
def hello_world():
    return 'Hello from Flask!'
 
def in_db(arr, value):
    for i in arr:
        if i[0] == value:
            return True
    return False
 
@app.route('/', methods=['POST'])
def processing():
    conn = sqlite3.connect('/home/vktrain/mysite/data.sqlite')
    c = conn.cursor()
    c.execute('''SELECT * from board''')
    result = c.fetchall()
 
    data = json.loads((request.data).decode('utf-8'))
 
    if 'type' not in data.keys():
        return 'not vk'
    if data['type'] == 'confirmation':
        return '475ba7f6'
    elif data['type'] == 'board_post_new' and in_db(result, data['object']['topic_id']):
        login = '***'
        password = '***'
        vk_session = vk_api.VkApi(login, password)
        vk_session.auth()
        vk = vk_session.get_api()
        c.execute('''SELECT last_num FROM board WHERE board_id={0}'''.format(data['object']['topic_id']))
        result = c.fetchall()
        clear_result = result[0][0]
        vk.board.editComment(group_id=data['group_id'],
                                        topic_id=data['object']['topic_id'],
                                        comment_id=data['object']['id'],
                                        message=clear_result)
        c.execute('''UPDATE board SET last_num={0} WHERE board_id={1}'''.format(clear_result+1, data['object']['topic_id']))
        c.commit()
        c.close()
        conn.close()
        return 'ok'
 
    else:
        c.close()
        conn.close()
        return 'ok'