完整代码如下 - 很简单，我想添加、删除或更新帖子 - 当我自己做其中一件事时它可以工作，但一起做的时候它会中断

我在 NodeJS MySQL 中搜索了很多，我用它来查询数据库

var mysql = require('mysql');

var connection = mysql.createConnection({
  host : 'localhost',
  port : 3306,
  database: 'nodeproject',
  user : 'noderoot',
  password : 'default'
});

var express = require('express');
var http = require('http');
var path = require('path');
var exphbs  = require('express3-handlebars');
var qs = require('querystring');

var app = express();

app.set('port', process.env.PORT || 8000);
app.set('views', path.join(__dirname, 'views'));
app.engine('handlebars', exphbs({defaultLayout: 'main'}));
app.set('view engine', 'handlebars');
app.use(express.favicon());
app.use(express.logger('dev'));
app.use(express.json());
app.use(express.urlencoded());
app.use(express.methodOverride());
app.use(app.router);
app.use(express.static(path.join(__dirname, 'public')));

// development only
if ('development' == app.get('env')) {
  app.use(express.errorHandler());
}

configQuery = function() {
  connection.config.queryFormat = function (query, values) {
  if (!values) return query;
  return query.replace(/\:(\w+)/g, function (txt, key) {
    if (values.hasOwnProperty(key)) {
      return this.escape(values[key]);
    }
    return txt;
  }.bind(this));
  };
}


index = function(req, res){
    /*connection.connect(function(err){
      if(err != null) {
        res.end('Error connecting to mysql:' + err+'\n');
      }
    });*/

    connection.query("SELECT * FROM posts", function(err, rows){
      if(err != null) {
        res.end("Query error:" + err);
      } else {
        var myOuterRows = [];
        for (var i = 0; i < rows.length; i++) {
            var myRows = rows[i];
            myOuterRows.push(myRows);
        };

        res.render('index', { 
            title: 'Express Handlebars Test',
            posts: myOuterRows
        });
      }
    });
};

addpost = function(req, res) {
    var post  = {
        id: req.body.post.id, 
        postTitle: req.body.post.postTitle, 
        postContent: req.body.post.postContent,
        published: req.body.post.published
    };

    connection.query('INSERT INTO posts SET ?', post, function(err, result) {
        console.log("Neat! you entered a post");
    });

    res.redirect("/");
}
editpost = function(req, res) {

    configQuery();

    var edit = {
        id: req.body.editpost.id, 
        postTitle: req.body.editpost.postTitle, 
        postContent: req.body.editpost.postContent
    };


    var queryTitle = connection.query("UPDATE posts SET ?", edit, function(err, result) {
        console.log("Neat! you editted a post")
    });

    res.redirect("/");
}
deletepost = function(req, res) {

    configQuery();

    var deleteThis  = {
        id: req.body.deletepost.id
    };

    console.log(deleteThis);

    var queryDelete = connection.query("DELETE FROM posts WHERE id = :id", {
        id: deleteThis.id
    });

    res.redirect("/");
}

app.get('/', index);

app.post('/', addpost);
app.post('/', editpost);
app.post('/', deletepost);

//app.get('/list', list);

http.createServer(app).listen(8000, function(){
  console.log('Express server listening on port ' + app.get('port'));


});

我得到的错误如下：

500 TypeError: Cannot read property 'id' of undefined
at editpost (C:\dev\ExpressHbsMysql\app.js:96:24)
at callbacks (C:\dev\ExpressHbsMysql\node_modules\express\lib\router\index.js:164:37)
at param (C:\dev\ExpressHbsMysql\node_modules\express\lib\router\index.js:138:11)
at pass (C:\dev\ExpressHbsMysql\node_modules\express\lib\router\index.js:145:5)
at Router._dispatch (C:\dev\ExpressHbsMysql\node_modules\express\lib\router\index.js:173:5)
at Object.router (C:\dev\ExpressHbsMysql\node_modules\express\lib\router\index.js:33:10)
at next (C:\dev\ExpressHbsMysql\node_modules\express\node_modules\connect\lib\proto.js:193:15)
at Object.methodOverride [as handle] (C:\dev\ExpressHbsMysql\node_modules\express\node_modules\connect\lib\middleware\methodOverride.js:48:5)
at next (C:\dev\ExpressHbsMysql\node_modules\express\node_modules\connect\lib\proto.js:193:15)
at C:\dev\ExpressHbsMysql\node_modules\express\node_modules\connect\lib\middleware\urlencoded.js:83:7