我正在开发简单的聊天应用程序，我想在mongoDb中存储消息。 但是当我运行此代码时，我收到错误。 无法读取未定义的属性＆＃39; _id＆＃39;我已经创建了一个集合呼叫聊天。
var MongoClient= require('mongodb').MongoClient;
var assert=require('assert');
var ObjectId= require('mongodb').ObjectId;
var bodyParser= require('body-parser');
var express = require('express'),
app=express();
server=require('http').createServer(app),
io= require('socket.io').listen(server),
app.use(bodyParser.urlencoded({extended:false}));
var mongo=require('mongodb');
users = {};
url='mongodb://localhost:27017/anant';
server.listen(9000, function(){
var host= server.address().address;
var port=server.address().port;
console.log("save app listen on http://%s:%s", host , port);
});
/*var server = app.listen(9000, function(){
var host= server.address().address;
var port=server.address().port;
console.log("save app listen on http://%s:%s", host , port);
});*/
app.get('/', function(req, res){
res.sendFile(__dirname + '/index.html');
});
io.sockets.on('connection', function(socket){
socket.on('new user', function(data , callback){
if(data in users){
callback(false);
}else{
callback(true);
socket.nickname= data;
users[socket.nickname]= socket;
updatenicknames();
}
});
io.sockets.on('send request', function(data , callback){
var name=data;
console.log(data);
});
socket.on('send message', function(data , callback){
var msg=data.trim();
if(msg.substr(0,3) === '/w '){
msg = msg.substr(3);
var ind = msg.indexOf(' ');
console.log(ind);
console.log("got it after ind ");
if(ind !== -1)
{
var name=msg.substr(0, ind);
var msg=msg.substring(ind + 1);
console.log(name);
console.log(msg);
if(name in users){
console.log("got it in if name condition");
users[name].emit('wishper', {msg: msg , nick: socket.nickname} );
console.log('whisper..! ');
} else
{
callback("enter a vlid user");
}
} else{
callback('please enter message for your wishper');
}
}else {
insertData(data);
io.sockets.emit('new message', {msg: msg , nick: socket.nickname} );
}
});
function updatenicknames(){
io.sockets.emit('usernames', Object.keys(users));
}
function insertData(data)
{
MongoClient.connect(url, function(err, db){
console.log(data);
db.collection('chat').save(data.msg , (err,result)=>{
if(err){
console.log("not inserted");
}else {
console.log("inserted");
}
});
});
}
socket.on('disconnect', function(data){
if(!socket.nickname) return;
delete users[socket.nickname];
updatenicknames();
});
});
答案 0 :(得分：2)
这是因为您将字符串 SELECT
wm.CID,
wm.DOC_ID,
wm.DOC_TYPE,
wml.SERIAL_NO,
wml.WH_MVT_NO,
wm.PROD_ID,
wm.LOT_CODE,
wm.WH_CODE,
wm.BIN_CODE,
wml.MVT_DATE,
wm.BATCH_NO,
wm.MVT_TYPE,
wm.PROD_NAME,
wm.COMMENT,
wm.REMARK,
wm.NOTE,
wm.INSTRUCTION
FROM
STOCK.WAREHOUSE_MVT_LINE wml
INNER JOIN
STOCK.WAREHOUSE_MVT wm
ON wml.CID=wm.CID
AND wml.WH_MVT_NO=wm.WH_MVT_NO
WHERE
wml.CID = 70200009
AND (
wm.MVT_TYPE != 'TFOUT'
AND wm.MVT_TYPE != '3TFOUT'
)
AND wml.SERIAL_NO IN (
(
SELECT
SERIAL_NO
FROM
STOCK.WAREHOUSE_MVT_LINE mvtLn
INNER JOIN
STOCK.WAREHOUSE_MVT mvt
ON mvtLn.CID = mvt.CID
AND mvtLn.PFC_CODE = mvt.PFC_CODE
AND mvtLn.WH_MVT_NO = mvt.WH_MVT_NO
where
mvtLn.CID = 70200009
AND mvtLn.PFC_CODE ='SG'
AND mvtLn.MVT_DATE >= '2016-04-01 00:00:00.0'
AND mvtLn.MVT_DATE <='2016-06-30 00:00:00.0'
AND mvt.WH_CODE = 'IDJKT'
AND mvt.BIN_CODE = 'IMP'
)AS a
INNER JOIN
(
SELECT
SERIAL_NO
FROM
STOCK.WAREHOUSE_MVT_LINE mvtLn
INNER JOIN
STOCK.WAREHOUSE_MVT mvt
ON mvtLn.CID = mvt.CID
AND mvtLn.PFC_CODE = mvt.PFC_CODE
AND mvtLn.WH_MVT_NO = mvt.WH_MVT_NO
where
mvtLn.CID = 70200009
AND mvtLn.PFC_CODE ='SG'
AND mvtLn.MVT_DATE >= '2016-01-01 00:00:00.0'
AND mvtLn.MVT_DATE <='2016-03-31 00:00:00.0'
AND mvt.WH_CODE = 'CL'
AND mvt.BIN_CODE = 'PSADEPOT'
)AS b
ON a.SERIAL_NO = b.SERIAL_NO
)
AND wm.MVT_DATE BETWEEN '2016-01-01 00:00:00.0' AND '2016-06-30 00:00:00.0'
ORDER BY
wml.SERIAL_NO,
wml.MVT_DATE
传递给data函数（根据您的代码判断，我猜您假设{{1}实际上是对象）。
然后您提供insertData，显然是data，作为data.msg方法的第一个参数，期望您提供有效的对象这里。
另请注意，您在新创建的文档上使用undefined方法，而不是使用save。
正如您在api documentation中所看到的，现在不推荐使用save。 （我猜您使用的是最新版本2.1）