Question

很抱歉，知道这些问题很受欢迎，但我无法在那里找到答案。

有输出

无法读取属性＆＃39;标题＆＃39;未定义的

链接到此文件中的帖子请求

const express = require('express');
const router = express.Router();

router.get('/', function (req, res, next) {
    let query = 'select event.id,   event.title,    event.description,  event.date, place.title as place,   organisator.title as organisator,   subcategory.title as subcategory from ((event inner join place on event.place_id = place.id) inner join organisator on event.organisator_id = organisator.id) inner join subcategory on event.subcategory_id = subcategory.id';
    res.locals.connection.query(query, function (error, results, fields) {
        if (error) throw error;
        res.render('index', { title: 'Events', data: results });
    });
});

router.post('/add', function (err, req, res) {
    const query = "insert into event (title, description, event.date, subcategory_id, place_id, organisator_id) values ('" + req.body.title + "','" + req.body.description + "','" + req.body.date + "',(SELECT id from subcategory WHERE title = '" + req.body.subcategory + "'),(SELECT id from place WHERE title = '" + req.body.place + "'),(SELECT id from organisator WHERE title = '" + req.body.organisator + "'))";
    connection.query(query, function (err) {
        if (err) {
            console.error(err);
            throw err;
        }
    });
});

抱歉滚动，只是有这样的疑问。找到一些答案，身体解析器应该在任何事情之前使用，但我想我不会有这样的问题。有我的app文件。

const express = require('express');
const path = require('path');
const logger = require('morgan');
const bodyParser = require('body-parser');

var app = express();

app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: false }));

app.use(logger('dev'));
app.use(express.static(path.join(__dirname, 'public')));

app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'ejs');

var mysql = require("mysql");
app.use(function(req, res, next){
    res.locals.connection = mysql.createConnection({
        host     : 'localhost',
        user     : 'root',
        password : 'Strange3865hum31315',
        database : 'minskevents'
    });
    res.locals.connection.connect();
    next();
});

app.use('/', require('./routes/index'));
app.use('/events', require('./routes/events'));

app.use(function(req, res, next) {
  var err = new Error('Not Found');
  err.status = 404;
  next(err);
});

app.use(function(err, req, res, next) {
  res.locals.message = err.message;
  res.locals.error = req.app.get('env') === 'development' ? err : {};
  res.status(err.status || 500);
  res.render('error');
});

var http = require('http');

var server = http.createServer(app);
server.listen(4000);
if(server.listening){
  console.log('Server is listening on port 4000');
}

module.exports = app;

我从html表格中获取数据

<form action="/events/add" method="POST">
        <input type="text" name="title" placeholder="Event name" />
        <input type="text" name="subcategory" placeholder="Category" />
        <input type="text" name="date" placeholder="Date" />
        <input type="text" name="place" placeholder="Place" />
        <input type="text" name="organisator" placeholder="Organisator" />
        <textarea name="description" placeholder="Description" onkeyup="adjust_textarea(this)"></textarea>
        <input type="submit" value="Add" />
      </form>

Answer 1

express中的错误处理程序必须有4 arguments, not 3。

因此，您的/add路线：

router.post('/add', function (err, req, res) {

实际上是第一个参数填充req（请求）的常规路由，第二个参数填充res（响应），第三个参数填充next函数。由于您将第二个参数命名为req，因此您创建了一个令人困惑的方案，其中req是响应，err是请求，res是下一个功能。

由于回复没有body属性且您已将回复命名为req，因此您的req.body.title正在尝试将属性设置为未定义的值（{ {1}}）。重命名您的参数body，我认为您会有更好的运气。

Answer 2

在get方法中，您将标题引用为event.title，但在帖子中引用为title。为什么呢？

无法阅读快递中的财产

2 个答案: