我是 Mongoose 的新手,我正在尝试制作一个涉及使用 Mongoose 的简单测试应用程序,以便熟悉它。我可以很好地加载“/”页面,但是当我提交表单时,它会保留在“/”页面上,直到我终止进程。 console.logs“之前”和“之后”打印,但期间从不打印。怎么了?
var express = require('express');
var mongoose = require('mongoose')
, db = mongoose.createConnection('localhost', 'testmongoose');
var connectdb = function(execute) {
db.on('error', console.error.bind(console, 'connection error:'));
db.once('open', function () {
execute();
});
};
connectdb(function () {
var postSchema = new mongoose.Schema({
body: String
});
var Post = db.model('Post', postSchema);
});
var app = express();
app.configure(function () {
//app.use(express.logger());
app.use(express.bodyParser());
app.use(express.static(__dirname + '/static'));
});
app.set('views', __dirname + '/views');
app.set('view engine','jade');
app.get('/', function(request, response) {
response.render('index');
});
app.post('/result', function(request, response) {
var text = request.body.text;
console.log("before!");
connectdb(function () {
console.log("during!");
var post = "test";
post = new Post({body: text});
response.render('result', {text: post.body});
});
console.log("after!");
});
app.listen(4000);
最佳答案
首先,由于 connectdb
是一个异步函数,因此它会立即返回并稍后运行其回调 - 这意味着您的 console.log
的顺序将是“之前!”然后!”然后“期间!”稍后。
也就是说,connectdb
并没有真正为您提供任何用处。 Mongoose 会自动缓冲命令直至连接,因此您可以将其视为同步接口(interface):
var express = require('express');
var mongoose = require('mongoose');
mongoose.connect('mongodb://localhost', 'testmongoose');
mongoose.connection.on('error', console.error.bind(console, 'connection error:'));
var postSchema = new mongoose.Schema({
body: String
});
var Post = mongoose.model('Post', postSchema);
var app = express();
app.configure(function () {
//app.use(express.logger());
app.use(express.bodyParser());
app.use(express.static(__dirname + '/static'));
});
app.set('views', __dirname + '/views');
app.set('view engine','jade');
app.get('/', function(request, response) {
response.render('index');
});
app.post('/result', function(request, response) {
var text = request.body.text;
var post = new Post({body: text});
response.render('result', {text: post.body});
});
app.listen(4000);
关于当我尝试从 Mongoose 访问 MongoDB 数据库时,Node.js Express 应用程序卡住,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/12047838/