Ошибка в боте Телеграмм

Такая проблема. Появляется после запуска бота.
Libraries

python 3.9
aiogram 3.1.1
PyMySQL 1.1.o
asyncio 3.4.3
MySQL 5.5.23
PMA 3.5.1

Cause exception while process update id=742053270 by bot id=6871058034
ProgrammingError: (1064, "You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ''users' WHERE 'user_id' = 1628358150' at line 1")
Traceback (most recent call last):
  File "C:\Users\lipuha\AppData\LPWKtcPjpxQzc26CxTtPFuQMNfm2RfEHfK\site-packages\aiogram\dispatcher\dispatcher.py", line 308, in _process_update
    response = await self.feed_update(bot, update, **kwargs)
  File "C:\Users\lipuha\AppData\LPWKtcPjpxQzc26CxTtPFuQMNfm2RfEHfK\site-packages\aiogram\dispatcher\dispatcher.py", line 157, in feed_update
    response = await self.update.wrap_outer_middleware(
  File "C:\Users\lipuha\AppData\LPWKtcPjpxQzc26CxTtPFuQMNfm2RfEHfK\site-packages\aiogram\dispatcher\middlewares\error.py", line 25, in __call__
    return await handler(event, data)
  File "C:\Users\lipuha\AppData\LPWKtcPjpxQzc26CxTtPFuQMNfm2RfEHfK\site-packages\aiogram\dispatcher\middlewares\user_context.py", line 27, in __call__
    return await handler(event, data)
  File "C:\Users\lipuha\AppData\LPWKtcPjpxQzc26CxTtPFuQMNfm2RfEHfK\site-packages\aiogram\fsm\middleware.py", line 41, in __call__
    return await handler(event, data)
  File "C:\Users\lipuha\AppData\LPWKtcPjpxQzc26CxTtPFuQMNfm2RfEHfK\site-packages\aiogram\dispatcher\event\telegram.py", line 120, in trigger
    return await wrapped_inner(event, kwargs)
  File "C:\Users\lipuha\AppData\LPWKtcPjpxQzc26CxTtPFuQMNfm2RfEHfK\site-packages\aiogram\dispatcher\event\handler.py", line 42, in call
    return await wrapped()
  File "C:\Users\lipuha\AppData\LPWKtcPjpxQzc26CxTtPFuQMNfm2RfEHfK\site-packages\aiogram\dispatcher\dispatcher.py", line 275, in _listen_update
    return await self.propagate_event(update_type=update_type, event=event, **kwargs)
  File "C:\Users\lipuha\AppData\LPWKtcPjpxQzc26CxTtPFuQMNfm2RfEHfK\site-packages\aiogram\dispatcher\router.py", line 116, in propagate_event
    return await observer.wrap_outer_middleware(_wrapped, event=event, data=kwargs)
  File "C:\Users\lipuha\AppData\LPWKtcPjpxQzc26CxTtPFuQMNfm2RfEHfK\site-packages\aiogram\dispatcher\router.py", line 111, in _wrapped
    return await self._propagate_event(
  File "C:\Users\lipuha\AppData\LPWKtcPjpxQzc26CxTtPFuQMNfm2RfEHfK\site-packages\aiogram\dispatcher\router.py", line 136, in _propagate_event
    response = await observer.trigger(event, **kwargs)
  File "C:\Users\lipuha\AppData\LPWKtcPjpxQzc26CxTtPFuQMNfm2RfEHfK\site-packages\aiogram\dispatcher\event\telegram.py", line 120, in trigger
    return await wrapped_inner(event, kwargs)
  File "C:\Users\lipuha\AppData\LPWKtcPjpxQzc26CxTtPFuQMNfm2RfEHfK\site-packages\aiogram\dispatcher\event\handler.py", line 42, in call
    return await wrapped()
  File "c:\Users\lipuha\Desktop\TG_Bot\main.py", line 19, in start
    if(not db.user_exists(message.from_user.id)):
  File "c:\Users\lipuha\Desktop\TG_Bot\db.py", line 22, in user_exists
    result = self.cur.execute("SELECT * FROM 'users' WHERE 'user_id' = %s", user_id).fetchall()
  File "C:\Users\lipuha\AppData\LPWKtcPjpxQzc26CxTtPFuQMNfm2RfEHfK\site-packages\pymysql\cursors.py", line 153, in execute
    result = self._query(query)
  File "C:\Users\lipuha\AppData\LPWKtcPjpxQzc26CxTtPFuQMNfm2RfEHfK\site-packages\pymysql\cursors.py", line 322, in _query
    conn.query(q)
  File "C:\Users\lipuha\AppData\LPWKtcPjpxQzc26CxTtPFuQMNfm2RfEHfK\site-packages\pymysql\connections.py", line 558, in query
    self._affected_rows = self._read_query_result(unbuffered=unbuffered)
  File "C:\Users\lipuha\AppData\LPWKtcPjpxQzc26CxTtPFuQMNfm2RfEHfK\site-packages\pymysql\connections.py", line 822, in _read_query_result
    result.read()
  File "C:\Users\lipuha\AppData\LPWKtcPjpxQzc26CxTtPFuQMNfm2RfEHfK\site-packages\pymysql\connections.py", line 1200, in read
    first_packet = self.connection._read_packet()
  File "C:\Users\lipuha\AppData\LPWKtcPjpxQzc26CxTtPFuQMNfm2RfEHfK\site-packages\pymysql\connections.py", line 772, in _read_packet
    packet.raise_for_error()
  File "C:\Users\lipuha\AppData\LPWKtcPjpxQzc26CxTtPFuQMNfm2RfEHfK\site-packages\pymysql\protocol.py", line 221, in raise_for_error
    err.raise_mysql_exception(self._data)
  File "C:\Users\lipuha\AppData\LPWKtcPjpxQzc26CxTtPFuQMNfm2RfEHfK\site-packages\pymysql\err.py", line 143, in raise_mysql_exception
    raise errorclass(errno, errval)
pymysql.err.ProgrammingError: (1064, "You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ''users' WHERE 'user_id' = 1628358150' at line 1")

main.py

import asyncio
from aiogram import Bot, Dispatcher, F
from aiogram.types import Message
from aiogram.filters import Command, CommandObject, CommandStart
from db import Database

from config import TOKEN_TELEGRAM

import markups as kb


bot = Bot(TOKEN_TELEGRAM, parse_mode="HTML")
dp = Dispatcher()

db = Database()

@dp.message(CommandStart())
async def start(message: Message):
    if(not db.user_exists(message.from_user.id)):
        db.add_user(message.from_user.id)
        await message.answer("Введите предпочитаемое имя: ")
    else:
        await message.answer("Приветуствую", reply_markup=kb.mainMenu)
@dp.message()
async def bot_message(message: Message):
    if (db.get_signup(message.from_user.id)=='set_nickname'):
        if "@" in message or '/' in message:
            await message.answer('В имени не должный присутсвтовать следующие знаки: @, /')
        elif len(message) > 15:
            await message.answer('Имя не должно превышать 15 символов!')
        else:
            db.set_nickname(message.from_user.id, message)
            db.set_signup(message.from_user.id, "done")
            await message.answer("Регистрация прошла успешно!", reply_markup=kb.mainMenu)
    else:
        await message.answer('Не пон(')

async def main():
    await bot.delete_webhook(drop_pending_updates=True)
    await dp.start_polling(bot)

if __name__ == '__main__':
    asyncio.run(main())

db.py

import pymysql
import pymysql.cursors

class Database:
    def __init__(self):
        self.con = pymysql.connect(
        host='localhost',
        port=3306, 
        user='root', 
        password='', 
        database='tgbot', 
        charset='utf8mb4', 
        cursorclass=pymysql.cursors.DictCursor
        )
        self.cur = self.con.cursor()
    def add_user(self, user_id):
    with self.con:
        self.cur.execute("INSERT INTO 'users' ('user_id') VALUE (%s)", user_id)

def user_exists(self, user_id):
    with self.con:
        result = self.cur.execute("SELECT * FROM 'users' WHERE 'user_id' = %s", user_id).fetchall()
        return bool(len(result))

def set_nickname(self, user_id, nickname):
    with self.con:
        return self.cur.execute("UPDATE 'users' SET 'nickname' = %s WHERE 'user_id' = %s", nickname, user_id)

def get_signup(self, user_id):
    with self.con:
        result = self.cur.execute("SELECT 'signup' FROM 'users' WHERE 'user_id' = %s", user_id,).fetchall()
        for row in result:
            signup = str(row[0])
        return signup
def set_signup(self, user_id, signup):
    with self.con:
        return self.cur.execute("UPDATE 'users' SET 'signup' = %s WHERE 'user_id' = %s", signup, user_id)