我不能使用post.find标签运行回调函数。每当我运行nodemon app.js时,它都会显示如下错误:
D:\Blog-with-Database-Starting-Files\node_modules\mongoose\lib\model.js:2048
throw new MongooseError('Model.find() no longer accepts a callback');
^
MongooseError: Model.find() no longer accepts a callback
at Function.find (D:\Blog-with-Database-Starting-Files\node_modules\mongoose\lib\model.js:2048:11)
at Object.<anonymous> (D:\Blog-with-Database-Starting-Files\app.js:57:6)
at Module._compile (node:internal/modules/cjs/loader:1254:14)
at Module._extensions..js (node:internal/modules/cjs/loader:1308:10)
at Module.load (node:internal/modules/cjs/loader:1117:32)
at Module._load (node:internal/modules/cjs/loader:958:12)
at Function.executeUserEntryPoint [as runMain] (node:internal/modules/run_main:81:12)
at node:internal/main/run_main_module:23:47
Node.js v18.15.0
[nodemon] app crashed - waiting for file changes before starting...
以下是我的app.js文件和ejs文件:
//jshint esversion:6
const express = require("express");
const bodyParser = require("body-parser");
const ejs = require("ejs");
const _ = require("lodash");
const mongoose = require("mongoose");
const homeStartingContent = "Lacus vel facilisis volutpat est velit egestas dui id ornare. Semper auctor neque vitae tempus quam. Sit amet cursus sit amet dictum sit amet justo. Viverra tellus in hac habitasse. Imperdiet proin fermentum leo vel orci porta. Donec ultrices tincidunt arcu non sodales neque sodales ut. Mattis molestie a iaculis at erat pellentesque adipiscing. Magnis dis parturient montes nascetur ridiculus mus mauris vitae ultricies. Adipiscing elit ut aliquam purus sit amet luctus venenatis lectus. Ultrices vitae auctor eu augue ut lectus arcu bibendum at. Odio euismod lacinia at quis risus sed vulputate odio ut. Cursus mattis molestie a iaculis at erat pellentesque adipiscing.";
const aboutContent = "Hac habitasse platea dictumst vestibulum rhoncus est pellentesque. Dictumst vestibulum rhoncus est pellentesque elit ullamcorper. Non diam phasellus vestibulum lorem sed. Platea dictumst quisque sagittis purus sit. Egestas sed sed risus pretium quam vulputate dignissim suspendisse. Mauris in aliquam sem fringilla. Semper risus in hendrerit gravida rutrum quisque non tellus orci. Amet massa vitae tortor condimentum lacinia quis vel eros. Enim ut tellus elementum sagittis vitae. Mauris ultrices eros in cursus turpis massa tincidunt dui.";
const contactContent = "Scelerisque eleifend donec pretium vulputate sapien. Rhoncus urna neque viverra justo nec ultrices. Arcu dui vivamus arcu felis bibendum. Consectetur adipiscing elit duis tristique. Risus viverra adipiscing at in tellus integer feugiat. Sapien nec sagittis aliquam malesuada bibendum arcu vitae. Consequat interdum varius sit amet mattis. Iaculis nunc sed augue lacus. Interdum posuere lorem ipsum dolor sit amet consectetur adipiscing elit. Pulvinar elementum integer enim neque. Ultrices gravida dictum fusce ut placerat orci nulla. Mauris in aliquam sem fringilla ut morbi tincidunt. Tortor posuere ac ut consequat semper viverra nam libero.";
const app = express();
mongoose.connect("mongodb://127.0.0.1:27017/blogDB", {useNewUrlParser: true})
app.set('view engine', 'ejs');
app.use(bodyParser.urlencoded({extended: true}));
app.use(express.static("public"));
const postSchema = {
title: String,
content: String
};
const Post = mongoose.model("Post", postSchema);
app.get("/", function(req, res){
Post.find({}).then(function(err, foundPosts){
if(err){
console.log(err)
}
else{
res.render("home", {
homeStartingContent: homeStartingContent,
posts: foundPosts
});
}
})
});
app.get("/about", function(req, res){
res.render("about", {aboutContent: aboutContent});
});
app.get("/contact", function(req, res){
res.render("contact", {contactContent: contactContent});
});
app.get("/compose", function(req, res){
res.render("compose");
});
Post.find({}, function(err, posts){
res.render("home", {
startingContent: homeStartingContent,
posts: posts
});
})
app.post("/compose", function(req, res){
const post = new Post({
title: req.body.postTitle,
content: req.body.postBody
});
post.save()
res.redirect("/");
});
app.get("/posts/:postName", function(req, res){
const requestedTitle = _.lowerCase(req.params.postName);
posts.forEach(function(post){
const storedTitle = _.lowerCase(post.title);
if (storedTitle === requestedTitle) {
res.render("post", {
title: post.title,
content: post.content
});
}
});
});
app.listen(3000, function() {
console.log("Server started on port 3000");
});
<%- include("partials/header"); -%>
<h1>Home</h1>
<p> <%= startingContent %> </p>
<% posts.forEach(function(post){ %>
<h1><%=post.title%></h1>
<p>
<%=post.content.substring(0, 100) + " ..."%>
<a href="/posts/<%=post.title%>">Read More</a>
</p>
<% }) %>
<%- include("partials/footer"); -%>
我已经将app.get(“/",function(req,res){}部分中的回调函数格式更改为Post.find({}).then(function(foundPosts),但它仍然不起作用。请建议任何替代方法,以便使回调函数正常运行。
1条答案
按热度按时间lyr7nygr1#
您使用的是哪个版本的Mongoose?在v6和更高版本中,他们已经停止了对回调函数的支持,以消除Promise和回调的混合。例如,这将抛出错误。
您需要使用
async/await
或Promises- async/await可能漏掉了一个括号/闭括号,但你明白了。