一旦編譯了模型''，編譯一次就不能覆蓋`User`模型

Question

你能幫助我嗎？我看不出這裏有什麼問題。

這裏是代碼片段從server.js：

var mongoose = require('mongoose'); 

var MongoClient = require('mongodb').MongoClient 
    , assert = require('assert'); 
var db = 'nodebook'; 
var url = '' 
mongoose.createConnection('mongodb://localhost/'+db); 

// The User 
    var User = mongoose.model('User', { 
    username: String, 
    password: String, 
    biography: String, 
    image: String, 
    }); 

這似乎每次 「noding」 server.js。 Btw。我是node.js/mongoose中的新手。

來自終端的錯誤：

/Users/davidnoldner/node_modules/mongoose/lib/index.js:360 
     throw new mongoose.Error.OverwriteModelError(name); 
    ^
OverwriteModelError: Cannot overwrite `User` model once compiled. 
    at Mongoose.model (/Users/davidnoldner/node_modules/mongoose/lib/index.js:360:13) 
    at Server.<anonymous> (/Users/davidnoldner/Librament/server.js:46:21) 
    at emitTwo (events.js:87:13) 
    at Server.emit (events.js:172:7) 
    at HTTPParser.parserOnIncoming [as onIncoming] (_http_server.js:533:12) 
    at HTTPParser.parserOnHeadersComplete (_http_common.js:103:23) 

也許有幫助 - mongod的控制檯：

2016-09-15T08:32:07.973+0200 W NETWORK [HostnameCanonicalizationWorker] Failed to obtain name info for: [ (2620:9b::5dd:4570, "nodename nor servname provided, or not known"), (2620:9b::5dd:4570, "nodename nor servname provided, or not known"), (192.168.0.16, "nodename nor servname provided, or not known"), (5.221.69.112, "nodename nor servname provided, or not known"), (192.168.0.16, "nodename nor servname provided, or not known"), (5.221.69.112, "nodename nor servname provided, or not known") ] 

謝謝！

Answer 1

初始化貓鼬模型時出錯，沒有遵循正確的語法和文檔。請參閱this鏈接上的mongoose文檔。

var mongoose = require('mongoose'); 

var MongoClient = require('mongodb').MongoClient 
    ,assert = require('assert'); 
var db = 'nodebook'; 
var url = '' 
mongoose.createConnection('mongodb://localhost:27017/'+db); 

const Schema = mongoose.Schema; 
// The User 
var User = mongoose.model('User', new Schema({ 
    username: String, 
    password: String, 
    biography: String, 
    image: String, 
}));