javascript - 如何在 express 中路由 CRUD 操作？

Question

我有以下用于 node.js、express 和使用 mongoose 的 MongoDB 连接的代码。

首先，我尝试了一个名为 server.js 的文件，它在没有 express 的情况下工作。但是现在我想用 express 来做，但它不起作用。

这只是一个在 mongo 数据库中读取和创建示例 Bear 对象的简单程序。

这是我的app.js

var express = require('express');
var path = require('path');
var favicon = require('serve-favicon');
var logger = require('morgan');
var cookieParser = require('cookie-parser');
var bodyParser = require('body-parser');

//var routes = require('./routes/index');
var users = require('./routes/users');
var mongoose = require('mongoose');
var db = mongoose.connect('localhost:27017/nodetest1');

//var Bear = require('./routes/users');


var app = express();

// view engine setup
app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'jade');

// uncomment after placing your favicon in /public
//app.use(favicon(path.join(__dirname, 'public', 'favicon.ico')));
app.use(logger('dev'));
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: true }));
app.use(cookieParser());
app.use(express.static(path.join(__dirname, 'public')));

var port = process.env.PORT || 8080;

// Make our db accessible to our router
app.use(function(req,res,next){
    req.db = db;
    next();
});

// ROUTES FOR OUR API
// =============================================================================
var router = express.Router();              // get an instance of the express Router

router.use(function(req,res,next){
  console.log('something is happening');
  next();
});

// test route to make sure everything is working (accessed at GET http://localhost:8080/api)
router.get('/', function(req, res) {
    res.json({ message: 'hooray! welcome to our api!' });   
});

// more routes for our API will happen here




// REGISTER OUR ROUTES -------------------------------
// all of our routes will be prefixed with /api

app.use('/', router);
app.use('/bears', users);

// START THE SERVER
// =============================================================================
app.listen(port);
console.log('Magic happens on port ' + port);


// catch 404 and forward to error handler
app.use(function(req, res, next) {
  var err = new Error('Not Found');
  err.status = 404;
  next(err);
});

// error handlers

// development error handler
// will print stacktrace
if (app.get('env') === 'development') {
  app.use(function(err, req, res, next) {
    res.status(err.status || 500);
    res.render('error', {
      message: err.message,
      error: err
    });
  });
}

// production error handler
// no stacktraces leaked to user
app.use(function(err, req, res, next) {
  res.status(err.status || 500);
  res.render('error', {
    message: err.message,
    error: {}
  });
});


module.exports = app;

这是我的 users.js

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

var Schema = mongoose.Schema;

var BearSchema = new Schema({
  name: String
});

module.exports = mongoose.model('Bear',BearSchema);


router.route('/bears')

    // create a bear (accessed at POST http://localhost:8080/api/bears)
    .post(function(req, res) {

        var bear = new Bear();      // create a new instance of the Bear model
        bear.name = req.body.name;  // set the bears name (comes from the request)

        // save the bear and check for errors
        bear.save(function(err) {
            if (err)
                res.send(err);

            res.json({ message: 'Bear created!' });
        });

    });
module.exports = router;

请告诉我如何路由 CRUD 操作。

Answer 1

你不能在一个文件中有两个 module.exports。位于文件底部的那个会重写所有其他的。

你需要两个文件，比如

controllers/users.js

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

router.route('/bears')

    // create a bear (accessed at POST http://localhost:8080/api/bears)
    .post(function(req, res) {

        var bear = new Bear();      // create a new instance of the Bear model
        bear.name = req.body.name;  // set the bears name (comes from the request)

        // save the bear and check for errors
        bear.save(function(err) {
            if (err)
                res.send(err);

            res.json({ message: 'Bear created!' });
        });

    });
module.exports = router;

模型/user.js

var mongoose = require('mongoose');
var Schema = mongoose.Schema;

var BearSchema = new Schema({
  name: String
});

module.exports = mongoose.model('Bear',BearSchema);

在您的 app.js 中，您可以这样做:

var user = require('controllers/user');
app.use('/users', user);

它的端点现在监听在 /users/bears

如果你在某处需要你的模型，只需加载它

var userModel = mongoose.model('User');

---

我建议下载并运行这个 template , 添加新功能更容易，当你看到它们是如何实现的