我尝试使用NextJS 13.4.12与mongoose 7.4.2我得到OverrideModelError有时当我从Web浏览器获取RestAPI。
我把这个项目上传到github：https://github.com/pzoli/homework4nextjs
My Difficulty. ts数据定义如下：

import mongoose, { Schema, model, Types } from "mongoose";

const difficultySchema = new Schema({
    name: {
        type: String,
        required: true,
    },
    value: {
        type: Number,
        required: true,
    },
});

export default mongoose.models.Difficulty || model("difficulty", difficultySchema);

我的dbConnect.ts是这样的：

import mongoose, { connect } from "mongoose";

let cached: undefined | Promise<void>;
export default () => {
  if (mongoose.connections && mongoose.connections[0].readyState)
    return Promise.resolve();

  if (!cached) {
    cached = connect(process.env.MONGODB_URI || 'mongodb://127.0.0.1:27017/quiz')
      .then(() => console.log("connected to database."))
      .catch((err) => console.log("could not connect to database", err));
  }
  return cached;
}

难度目录中的. tsx页为：

"use client";

import React from 'react'
import { DataTable } from "primereact/datatable"
import { Column } from "primereact/column"
import { useQuery } from '@tanstack/react-query';
import Link from 'next/link';

export default function Difficulty() {

    const { data: difficultyValues, status: dataFetchStatus, isLoading: isDataLoading } = useQuery({
        queryKey: ["difficulty"],
        queryFn: async () => {
            const res = await fetch(`/api/difficulty`, { cache: "no-cache" });
            return res.json();
        }
    });

    return (
        <>
            <DataTable value={difficultyValues} loading={isDataLoading}>
                <Column field='name' header="Name"></Column>
            </DataTable>
            <Link href="/">Home</Link>
        </>
    )
}

route. ts如下：

import Difficulty from "@/app/api/models/Difficulty";
import connection from "@/app/lib/dbConnect";
import { NextResponse } from "next/server";

export async function GET() {
    await connection();
    let result = await Difficulty.find({});
    return NextResponse.json(result);
}

我的UserAnswer.ts代码如下（在错误消息中引用，但未使用任何route. ts）：

import mongoose, { Schema, model, Types } from "mongoose";

const userAnswerSchema = new Schema({
    question_answer_id: {
        type: Types.ObjectId,
        required: true,
        ref: 'questionanswer'
    },
    recorded_time: {
        type: Date,
        required: false,
    },
    user_id: {
        type: Types.ObjectId,
        required: true,
        ref: 'user'
    },
    thinkingtime: {
        type: Number,
        required: true,
    },
});

export default mongoose.models.UserAnswer || model("useranswer", userAnswerSchema);;

整个错误消息是：

• [31merror [39m覆盖模型错误：编译后无法覆盖useranswer模型。在 Mongoose 型号（E：\work\integrity\Homeworks\homework4nextjs\node_modules\mongoose\lib\index.js：第五百六十三章：13）在eval（webpack-internal：///（rsc）/./app/API/models/UserAnswer。TS：28：184）在（rsc）/。/app/API/models/UserAnswer。ts（E：\work\integrity\Homeworks\homework4nextjs.next\server\app\api\question\route.js：八十二：1）atwebpack_require（E：\work\integrity\Homeworks\homework4nextjs. next\server\webpack-runtime。js：三十三：42）在eval（webpack-internal：///（rsc）/./app/API/models/models. TS：7：69）在（rsc）/。/app/API/models/models答案。ts（E：\work\integrity\Homeworks\homework4nextjs.next\server\app\api\question\route.js：七十二：1）atwebpack_require（E：\work\integrity\Homeworks\homework4nextjs. next\server\webpack-runtime。js：三十三：42）在eval（webpack-internal：/（rsc）/./app/API/models/Question. TS：7：73）在（rsc）/。/app/API/models/Question. ts（E：\work\integrity\Homeworks\homework4nextjs.next\server\app\api\question\route.js：六十二：1）atwebpack_require（E：\work\integrity\Homeworks\homework4nextjs. next\server\webpack-runtime。js：三十三：42）在eval（webpack-internal：/（rsc）/./app/API/question/route。ts：5：82）在（rsc）/。/app/API/question/route。ts（E：\work\integrity\Homeworks\homework4nextjs.next\server\app\api\question\route.js：九十二：1）atwebpack_require（E：\work\integrity\Homeworks\homework4nextjs. next\server\webpack-runtime。js：三十三：42）在eval（webpack-internal：/（rsc）/./node_modules/next/dist/build/webpack/loaders/next-app-loader. js？name = app%2Fapi%2Fquestion%2Froute&page =%2Fapi%2Fquestion%2Froute&appPaths =& pagePath = private-next-app-dir % 2Fapi % 2Fquestion%2Froute. ts & appDir = E%3A%5Cwork%5Cintegrity%5CHomeworks%5Chomework4nextjs%5Capp&pageExtensions = tsx & pageExtensions = ts & pageExtensions = jsx & pageExtensions = js & rootDir = E%3A%5Cwork%5Cintegrity%5CHomeworks%5Chomework4nextjs&isDev = true & tsconfigPath = tsconfig。json & basePath =& assetPrefix =& nextConfigOutput =& preferredRegion =& middlewareConfig = e30%3D!：16：126）at（rsc）/./node_modules/next/dist/build/webpack/loaders/next-app-loader. js？name = app%2Fapi%2Fquestion%2Froute&page =%2Fapi%2Fquestion%2Froute&appPaths =& pagePath = private-next-app-dir % 2Fapi % 2Fquestion%2Froute. ts & appDir = E%3A%5Cwork%5Cintegrity%5CHomeworks%5Chomework4nextjs%5Capp&pageExtensions = tsx & pageExtensions = ts & pageExtensions = jsx & pageExtensions = js & rootDir = E%3A%5Cwork%5Cintegrity%5CHomeworks%5Chomework4nextjs&isDev = true & tsconfigPath = tsconfig。json & basePath =& assetPrefix =& nextConfigOutput =& preferredRegion =& middlewareConfig = e30%3D!（E：\work\integrity\Homeworks\homework4nextjs.next\server\app\api\question\route.js：42：1）atwebpack_require（E：\work\integrity\Homeworks\homework4nextjs. next\server\webpack-runtime. js：33：42）atwebpack_exec（E：\work\integrity\Homeworks\homework4nextjs.next\server\app\api\question\route.js：692：39）at E：\work\integrity\Homeworks\homework4nextjs.next\server\app\api\question\route.js：693：28 at Object.（E：\work\integrity\Homeworks\homework4nextjs.next\server\app\api\question\route.js：第六百九十六章：（3）模块。_compile（e：\work\integrity\Homeworks\homework4nextjs\lib\internal\modules\cjs\loader.js：1255：14）at Module._extensions..js（e：\work\integrity\Homeworks\homework4nextjs\lib\internal\modules\cjs\loader.js：1309：（10）模块。负载（e：\work\integrity\Homeworks\homework4nextjs\lib\internal\modules\cjs\loader.js：1113：32）在模块。_load（e：\work\integrity\Homeworks\homework4nextjs\lib\internal\modules\cjs\loader.js：960：（12）模块。require（e：\work\integrity\Homeworks\homework4nextjs\lib\internal\modules\cjs\loader.js：一一三七：19）at require（e：\work\integrity\Homeworks\homework4nextjs\lib\internal\modules\helpers.js：一百二十一：18）按要求页（e：\work\integrity\Homeworks\homework4nextjs\node_modules\next\dist\server\require.js：一百一十二：75）在e：\work\integrity\Homeworks\homework4nextjs\node_modules\next\dist\server\load-components。js：八十：84在过程中processTicksAndRejections（e：\work\integrity\Homeworks\homework4nextjs\lib\internal\process\task_processes.js：九十五：5）在100c负载下，Impl（e：\work\integrity\Homeworks\homework4nextjs\node_modules\next\dist\server\load-components。js：八十：26）在DevServer上。findPageServiceImpl（E：\work\integrity\Homeworks\homework4nextjs\node_modules\next\dist\server\next-server。js：四百三十四：36）{name："OverwriteModelError"，摘要：未定义，堆栈：'OverwriteModelError：无法覆盖useran…dules\next\dist\server\next-server.js:434:36)', message: 'Cannot overwrite useranswer "model once compiled."，Symbol（NextjsError）：服务器

我使用“npm run dev”命令运行项目。如果我运行“npm run build”和“npm run start”，错误就像我测试的那样消失了。错误不是第一次出现，有时需要刷新页面。请帮助我了解如何正确使用它。