node.js - 按 Id 显示 React 属性

Question

我有多个项目，但无法按 ID 显示每个项目页面中的每个属性。 (使用 Nodejs、Reactjs、MongoDB...) 它给出了一个错误

Cast to ObjectId failed for value ":id" at path "_id" for model "project"

还有这个console.log:

console.log('-----------PROJECTS byId-----------', projects);

给我undefined

我的路线:

const express = require('express'),
Projects = require('../models/projects.js'),
app = express.Router();
exports.render_projects_byId = (req, res) => {
let id = req.params.id;

Projects.findById(id).exec((err, projects) => {
    if (err) {
        console.log(err);
    }
    console.log('-----------PROJECTS byId-----------', projects);
    res.json(projects)
  });
};

我的项目页面将按其自己的 ID 显示项目属性

import React, { Component } from 'react';
import { NavLink } from 'react-router-dom';

import './Project.css';



class Project extends Component {
    state = {
     title : '',
     typeOfProduction: ''
    };

componentDidMount() {

    fetch('/dashboard/projects/:id')
    .then(response => { return response.json()
        .then(projects => {
            console.log(projects);
            this.setState({
                title: this.state.title,
                typeOfProduction: this.state.typeOfProduction
            })      
        })
    }).catch(error => console.error('Error:', error));
}

render() {
 console.log("This.state.projects " + this.state.projects);

    return (

        <div>
            <section className="Project container">
                  <h1>
                  {this.state.title} oi
                  </h1>
                  <h1>
                  {this.state.typeOfProduction} oi
                  </h1>
            </section>
        </div>
    );

    }
}

export default Project;

我的项目模型架构:

var mongoose = require("mongoose");

var projectSchema = new mongoose.Schema({

   title: String,
   typeOfProduction: String
})

module.exports = mongoose.model("Projects", projectSchema);

Answer 1

“CastError:模型“project”的路径“_id”处的值“{ id: ':id' }”转换为 ObjectId 失败

您正在发送一个对象，但它需要一个字符串。您应该尝试 Projects.findById(id) ....