main.py當我在路線之外使用cursor.execute..時，它正在工作。import mysql.connectorfrom flask import Flask, render_template, request, session, redirect, url_for, make_responseMySQL = mysql.connector.connect(    user='root',    password='password',    host='localhost',    database='dbname',    use_pure=True)cursor = MySQL.cursor(prepared=True)@app.route("/bridge", methods=["POST"])def bridge():    if request.get_json()["for"] == "signUp":        if request.get_json()["type"] == "existence":            cursor.execute("SELECT id FROM users WHERE eMail=%s", (request.get_json()["details"]["eMail"], ))            print("----------------- {}".format(cursor.fetchone()))    print(request.get_json()["details"]["eMail"])    return make_response(json.dumps({"Res"}), 200)cursor.close()MySQL.close()錯誤cursor.execute("從電子郵件中選擇 id=%s", (request.get_json()["details"]["eMail"], )) 文件 "C:\Users\woxro\AppData\Local\Programs\ Python\Python38-32\Lib\site-packages\mysql\connector\cursor.py”，第 1186 行，執行 charset = self._connection.charset AttributeError: 'NoneType' 對象沒有屬性 'charset'