javascript - 路由器在 Express.js 中返回 404

Question

我目前正在学习并且是 Node.js 的新手。我正在尝试构建一个简单的 REST API 并且当前在尝试发布到 postman 中的特定路线以测试数据是否已成功发送到 时收到 error 404 >Mongo 数据库。我确定我错过了什么。我已经仔细检查了我所有的路线，它们看起来都很好。它在我发出 get 请求时有效，而在我发出 post 请求时失败。

这是我的 app.js

var createError = require('http-errors');
var express = require('express');
var path = require('path');
var cookieParser = require('cookie-parser');
var bodyParser = require('body-parser');
var mongoose = require('mongoose');
var logger = require('morgan');
var indexRouter = require('./routes/index');
var usersRouter = require('./routes/users');
var Developer = require('./models/developers');
var app = express();

// view engine setup
app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'pug');
app.use(logger('dev'));
app.use(express.json());
app.use(express.urlencoded({ extended: false }));
app.use(cookieParser());
app.use(bodyParser.urlencoded({ extended: true}));
app.use(express.static(path.join(__dirname, 'public')));
app.use(bodyParser.json());
app.use('/', indexRouter);
app.use('/users', usersRouter);

// Connect to DB
mongoose.connect('mongodb://127.0.0.1:27017');

// API Routes
var router = express.Router();

// Routes will be prefixed with /api
app.use('/api', router);

// catch 404 and forward to error handler
app.use(function(req, res, next) {
  next(createError(404));
});

// error handler
app.use(function(err, req, res, next) {
  // set locals, only providing error in development
  res.locals.message = err.message;
  res.locals.error = req.app.get('env') === 'development' ? err : {};

  // render the error page
  res.status(err.status || 500);
  res.render('error');
});

module.exports = app;

// Test Route
router.get('/', function (req, res) {
  res.json({message: 'Welcome to my simple API!'});
});

router.route('/developers')
    .post(function (req, res) {
      var developer = new Developer(); // New instance of sa developer
      developer.firstName = req.body.firstName;
      developer.lastName = req.body.lastName;
      developer.jobTitle = req.body.jobTitle;

      developer.save(function (err) {
        if (err) {
          res.send(err);
        } else {
          res.json('Developer was successfully fetched');
        }
      });
    })

    .get(function (req, res) {
      Developer.find(function (err, developers) {
        if (err) {
          res.send(err);
        } else
          res.json(developers);
      });
    });

router.route('/developer/:developer_id')
    .get(function (req, res) {
      Developer.findById(res.params.developer_id, function (err, developer) {
        if (err) {
          res.send(err);
        }
        res.json(developer);
      });
    });

router.route('/developer/firstName/:firstName')
    .get(function (req, res) {
      Developer.find({firstName:res.params.firstName}, function (err, developer) {
        if (err) {
          res.send(err);
        }
        res.json(developer);
      });
    });

我的模型是 developer.js

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

var DevelopersSchema = new Schema({
   firstName: String,
   lastName: String,
   jobTitle: String
});

module.exports = mongoose.model('Developers', DevelopersSchema);

Answer 1

连接数据库，而不是

mongoose.connect('mongodb://127.0.0.1:27017');

使用，

mongoose.connect('mongodb://127.0.0.1:27017/yourDatabaseName');

检查 doc .

Mongoose 数据库连接需要数据库名称 connect()方法。

你的最终app.js应该是这样的，

var createError = require('http-errors');
var express = require('express');
var path = require('path');
var cookieParser = require('cookie-parser');
var bodyParser = require('body-parser');
var mongoose = require('mongoose');
var logger = require('morgan');
var indexRouter = require('./routes/index');
var usersRouter = require('./routes/users');
var Developer = require('./models/developers');
var app = express();

// view engine setup
app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'pug');
app.use(logger('dev'));
app.use(express.json());
app.use(express.urlencoded({ extended: false }));
app.use(cookieParser());
app.use(bodyParser.urlencoded({ extended: true}));
app.use(express.static(path.join(__dirname, 'public')));
app.use(bodyParser.json());
app.use('/', indexRouter);
app.use('/users', usersRouter);

// Connect to DB
mongoose.connect('mongodb://127.0.0.1:27017/my_unique_data_base_name');

// API Routes
var router = express.Router();

// Routes will be prefixed with /api
app.use('/api', router);

// catch 404 and forward to error handler
app.use(function(req, res, next) {
  next(createError(404));
});

// error handler
app.use(function(err, req, res, next) {
  // set locals, only providing error in development
  res.locals.message = err.message;
  res.locals.error = req.app.get('env') === 'development' ? err : {};

  // render the error page
  res.status(err.status || 500);
  res.render('error');
});

module.exports = app;

// Test Route
router.get('/', function (req, res) {
  res.json({message: 'Welcome to my simple API!'});
});

router.route('/developers')
    .post(function (req, res) {
      var developer = new Developer(); // New instance of sa developer
      developer.firstName = req.body.firstName;
      developer.lastName = req.body.lastName;
      developer.jobTitle = req.body.jobTitle;

      developer.save(function (err) {
        if (err) {
          res.send(err);
        } else {
          res.json('Developer was successfully fetched');
        }
      });
    })

    .get(function (req, res) {
      Developer.find(function (err, developers) {
        if (err) {
          res.send(err);
        } else
          res.json(developers);
      });
    });

router.route('/developer/:developer_id')
    .get(function (req, res) {
      Developer.findById(res.params.developer_id, function (err, developer) {
        if (err) {
          res.send(err);
        }
        res.json(developer);
      });
    });

router.route('/developer/firstName/:firstName')
    .get(function (req, res) {
      Developer.find({firstName:res.params.firstName}, function (err, developer) {
        if (err) {
          res.send(err);
        }
        res.json(developer);
      });
    });