我正在嘗試使用配置我的歡迎活動sqlite3。我編寫了以下代碼：import discordfrom discord.ext import commands, tasksimport discord.utilsimport asyncioimport datetimeimport sqlite3class WelCog(commands.Cog, name='Welcome') :    def __init__(self,bot):        self.bot = bot    @commands.Cog.listener()    async def on_member_join(self,member):        db = sqlite3.connect('main.sqlite')        cursor = db.cursor()        cursor.execute(f"SELECT channel_id FROM main WHERE guild_id = {member.guild.id}")        result =  cursor.fetchone()        if result is None:            return        else:            cursor.execute(f"SELECT msg FROM main WHERE guild_id = {member.guild.id}")            result1 =  cursor.fetchone()            members = len(list(member.guild.members))            mention = member.mention            user = member.name            guild=member.guild            embed = discord.Embed(color=0x0ff7dc, description=str(result1[0]).format(members=members, mention=mention, user=user, guild=guild))            embed.set_thumbnail(url=f"{member.avatar_url}")            embed.set_author(name=f"{member.name}", icon_url=f"{member.avatar_url}")            embed.set_author(name=f"{member.guild}", icon_url=f"{member.guild.icon_url}")            channel = self.bot.get_channel(id=int(result[0]))            await channel.send(embed=embed)            @commands.group(invoke_without_command=True)    async def welcome(self,ctx):        await ctx.send('Available Setup Commands: \nwelcome channel <#channel>\n welcome text <message>')    @welcome.command()    async def channel(self, ctx, channel:discord.TextChannel):        if ctx.message.author.guild_permissions.manage_messages:            db = sqlite3.connect('main.sqlite')            cursor = db.cursor()            cursor.execute(f"SELECT channel_id FROM main WHERE guild_id = {ctx.guild.id}")            result =  cursor.fetchone()我嘗試了很多方法來解決這個問題，但遺憾的是我無法解決。