TypeError: Cannot read properties of null (reading '_id')

Question

所以我试图从 mongodb 检索文档，但后来出现了这个错误我不知道它是数据库错误还是代码错误所以有帮助吗？

Encountered error on event listener "guildMemberAdd" for event "guildMemberAdd" at path "D:\Project\Troll Kick Bot\bin\listeners\guildMemberAdd.js" TypeError: Cannot read properties of null (reading '_id')
    at GuildMemberAddListener.<anonymous> (D:\Project\Troll Kick Bot\bin\listeners\guildMemberAdd.js:34:36)
    at Generator.next (<anonymous>)
    at fulfilled (D:\Project\Troll Kick Bot\bin\listeners\guildMemberAdd.js:9:58)
    at processTicksAndRejections (node:internal/process/task_queues:96:5)

guildMemberAdd.ts

import { Command } from "@sapphire/framework";
import { Message } from "discord.js";
import mongoose from "mongoose";
import { victim } from "../schema/victim";

export class Victim extends Command {
    public constructor(context: Command.Context, options: Command.Options) {
        super(context, {
            ...options,
            name: 'victim',
            description: 'kicks the victim without mercy' 
        })
    };

    public async messageRun(message: Message) {
        await mongoose.connect(process.env.Mongoose!);
        const victimUser = message.mentions.members!.first();
        const find = await victim.findOne({ _id: victimUser?.id});
        if (find) {
          return message.reply('brother that guy is already in our hitlist')
        };
        try {
            await new victim({ 
                _id: victimUser?.id,
                guildId: message.guild?.id
             }).save();
        } catch(e) {
            console.error(e)
        } finally {
            mongoose.connection.close()
        }
    }
}

Answer 1

在这行代码 await victim.findOne({ _id: victimUser?.id}); 中，victimUser?.id 似乎为您提供了一个 null 值。然后 Mongoose 似乎恐慌地说 - 你要我找到一个 _id 为空的文档。因此错误更多的是 - 为什么你得到一个 null for victimUser?.id。检查传递给函数 messageRun 的数据是否首先具有该字段 id。

TypeError: Cannot read properties of null (reading '_id')

TypeError: Cannot read properties of null (reading '_id')

javascript

node.js

mongodb

mongoose

discord.js