Mongoose报错：Model.find()不再支持回调函数，请求排查解决

报错Model.find() no longer accept a call back是因为你使用的Mongoose版本为6.x及以上，该版本已彻底移除了对CRUD方法回调函数的支持，所有查询操作现在仅返回Promise对象，不再接受回调参数。

你需要把代码中所有用回调的Mongoose操作改成async/await语法，以下是修改后的完整代码：

//jshint esversion:6 

const express = require("express");
const bodyParser = require("body-parser");
const mongoose = require("mongoose");
const _ = require("lodash");

const app = express();

app.set('view engine', 'ejs');

app.use(bodyParser.urlencoded({extended: true}));
app.use(express.static("public"));

// 连接MongoDB，新版本无需额外配置参数，用Promise处理连接结果
mongoose.connect("mongodb://localhost:27017/todolistDB")
.then(() => console.log("成功连接MongoDB"))
.catch(err => console.log("MongoDB连接失败:", err));

const itemsSchema = {
  name: String
};

const Item = mongoose.model("Item", itemsSchema);

const item1 = new Item({
  name: "Welcome to your todolist!"
});

const item2 = new Item({
  name: "Hit the + button to add a new item."
});

const item3 = new Item({
  name: "<-- Hit this to delete an item."
});

const defaultItems = [item1, item2, item3];

const listSchema = {
  name: String,
  items: [itemsSchema]
};

const List = mongoose.model("List", listSchema);

// 首页路由：改用async/await
app.get("/", async function(req, res) {
  try {
    const foundItems = await Item.find({});
    if (foundItems.length === 0) {
      await Item.insertMany(defaultItems);
      console.log("Successfully saved default items to DB.");
      res.redirect("/");
    } else {
      res.render("list", {listTitle: "Today", newListItems: foundItems});
    }
  } catch (err) {
    console.log("获取数据失败:", err);
    res.status(500).send("服务器内部错误");
  }
});

// 自定义列表路由：改用async/await
app.get("/:customListName", async function(req, res){
  const customListName = _.capitalize(req.params.customListName);
  try {
    const foundList = await List.findOne({name: customListName});
    if (!foundList){
      // 创建新列表
      const list = new List({
        name: customListName,
        items: defaultItems
      });
      await list.save();
      res.redirect("/" + customListName);
    } else {
      // 展示已有列表
      res.render("list", {listTitle: foundList.name, newListItems: foundList.items});
    }
  } catch (err) {
    console.log("访问自定义列表失败:", err);
    res.status(500).send("服务器内部错误");
  }
});

// 添加项路由：改用async/await
app.post("/", async function(req, res){
  const itemName = req.body.newItem;
  const listName = req.body.list;

  const item = new Item({
    name: itemName
  });

  try {
    if (listName === "Today"){
      await item.save();
      res.redirect("/");
    } else {
      const foundList = await List.findOne({name: listName});
      foundList.items.push(item);
      await foundList.save();
      res.redirect("/" + listName);
    }
  } catch (err) {
    console.log("添加项失败:", err);
    res.status(500).send("服务器内部错误");
  }
});

// 删除项路由：改用async/await
app.post("/delete", async function(req, res){
  const checkedItemId = req.body.checkbox;
  const listName = req.body.listName;

  try {
    if (listName === "Today") {
      await Item.findByIdAndRemove(checkedItemId);
      console.log("Successfully deleted checked item.");
      res.redirect("/");
    } else {
      await List.findOneAndUpdate({name: listName}, {$pull: {items: {_id: checkedItemId}}});
      res.redirect("/" + listName);
    }
  } catch (err) {
    console.log("删除项失败:", err);
    res.status(500).send("服务器内部错误");
  }
});

app.get("/about", function(req, res){
  res.render("about");
});

app.listen(3000, function() {
  console.log("Server started on port 3000");
}); 

关键修改点说明 #

• 所有Mongoose查询操作（find、findOne、insertMany、save、findByIdAndRemove、findOneAndUpdate）都改用async/await语法包裹，并通过try/catch捕获错误
• MongoDB连接部分改用Promise的then/catch处理连接状态，移除了过时的useNewUrlParser配置（新版本已默认启用）
• 保留了原有业务逻辑，仅替换了异步操作的写法

内容的提问来源于stack exchange，提问作者Aman Sharma