javascript - 如何使用 mongodb MongoClient 发出 GET 请求？
问题描述
我写了一个函数：
function findAll(collection) {
var MongoClient = require('mongodb').MongoClient;
var url = "mongodb://localhost/";
MongoClient.connect(url, function(err, db, res) {
if (err) throw err;
var dbo = db.db("airport");
dbo.collection(collection).find({}).toArray(function(err, res, result) {
if (err) throw err;
return result;
});
db.close();
});
}
我在我的 GET 请求中使用：
app.get('/api/tourists', (req,res) => {
res.send(findAll("tourists"))
});
问题是：它不会在邮递员中发送它作为响应。当我在 addFunction 中将返回结果更改为 console.log(result) 时，它的结果实际上会记录到控制台，所以我知道这个函数正在工作。那么为什么它不能作为 HTTP 请求工作呢？该功能基于POST请求，类似
function addToDb(object, collection) {
var MongoClient = require('mongodb').MongoClient;
var url = 'mongodb://localhost/';
MongoClient.connect(url, object, collection, function(err, db) {
if (err) throw err;
var dbo = db.db("airport");
if (object.length > 1) {
dbo.collection(collection).insertMany(object, function(err, res) {
if (err) throw err;
console.log(object.length + " documents inserted");
db.close();
});
}
else {
dbo.collection(collection).insertOne(object, function(err, res) {
if (err) throw err;
console.log("1 document inserted");
db.close();
});
}
});
}
app.post('/api/tourists', (req, res) => {
/*
const { error } = validateCourse(req.body);
if (error) {
res.status(404).send('The course with given id do not exist');
return;
}
*/
const tourist = [{
id: tourists.length + 1,
name: req.body.name,
surname: req.body.surname,
gender: req.body.gender,
country: req.body.country,
birthDate: req.body.birthDate,
listOfFlightsById: req.body.listOfFlightsById
},];
tourists.push(tourist);
addToDb(tourist, "tourists")
res.send(tourist);
});
它似乎正在工作，意味着 POST 请求没有显示任何错误（除了
Listen on port 3000 ...
the options [id] is not supported
the options [name] is not supported
the options [surname] is not supported
the options [gender] is not supported
the options [country] is not supported
the options [birthDate] is not supported
the options [listOfFlightsById] is not supported
在终端中，但它在 Postman 中显示有效响应。在我开始重写 GET 方法之前，旧的 GET 从未显示我在重置之前发布的参数，我认为这是因为 GET 正在发送当前对象，而不是来自数据库的对象。所以我想发出一个 GET 请求，直接从 mongodb 获得响应
@Trevor Varwig 我尝试了您的代码，但它不起作用。输出和以前一样：Postman 没有响应，左侧面板没有新请求，但终端没有错误。但是后来我尝试了 POST 请求（它给出了有效的响应），之后 GET 请求在终端中导致了此错误并导致崩溃：
the options [0] is not supported
/home/nedlo/node_full/expr_demo/node_modules/mongodb/lib/operations/mongo_client_ops.js:466
throw err;
^
MongoError: doc parameter must be an object
at Function.create (/home/nedlo/node_full/expr_demo/node_modules/mongodb/node_modules/mongodb-core/lib/error.js:43:12)
at insertOne (/home/nedlo/node_full/expr_demo/node_modules/mongodb/lib/operations/collection_ops.js:847:18)
at executeOperation (/home/nedlo/node_full/expr_demo/node_modules/mongodb/lib/utils.js:420:24)
at Collection.insertOne (/home/nedlo/node_full/expr_demo/node_modules/mongodb/lib/collection.js:463:10)
at /home/nedlo/node_full/expr_demo/index.js:26:33
at result (/home/nedlo/node_full/expr_demo/node_modules/mongodb/lib/utils.js:414:17)
at executeCallback (/home/nedlo/node_full/expr_demo/node_modules/mongodb/lib/utils.js:406:9)
at err (/home/nedlo/node_full/expr_demo/node_modules/mongodb/lib/operations/mongo_client_ops.js:286:5)
at connectCallback (/home/nedlo/node_full/expr_demo/node_modules/mongodb/lib/operations/mongo_client_ops.js:241:5)
at process.nextTick (/home/nedlo/node_full/expr_demo/node_modules/mongodb/lib/operations/mongo_client_ops.js:463:7)
at process._tickCallback (internal/process/next_tick.js:61:11)
这是整个代码：
//import connect from './db.js';
//import logger from 'morgan';
const Joi = require('joi');
const express = require('express');
const app = express();
app.use(express.json());
const mongoose = require('mongoose');
mongoose.connect('mongodb://localhost/airport')
const db = mongoose.connection
function addToDb(object, collection) {
var MongoClient = require('mongodb').MongoClient;
var url = 'mongodb://localhost/';
MongoClient.connect(url, object, collection, function(err, db) {
if (err) throw err;
var dbo = db.db("airport");
if (object.length > 1) {
dbo.collection(collection).insertMany(object, function(err, res) {
if (err) throw err;
console.log(object.length + " documents inserted");
db.close();
});
}
else {
dbo.collection(collection).insertOne(object, function(err, res) {
if (err) throw err;
console.log("1 document inserted");
db.close();
});
}
});
}
function findAll(collection, cb) {
var MongoClient = require('mongodb').MongoClient;
var url = "mongodb://localhost/";
MongoClient.connect(url, function(err, db, res) {
if (err) throw err;
var dbo = db.db("airport");
dbo.collection(collection).find({}).toArray(function(err, res, result) {
if (err) throw err;
cb(result)
});
db.close();
});
}
const tourists = [
{id: 1, name: 'Ala', surname: 'maKota', gender: 'Male', country: 'Poland', birthDate: '19.03.1993', listOfFlightsById: [1]},
{id: 2, name: 'Ala', surname: 'maKota', gender: 'Male', country: 'Poland', birthDate: '19.03.1993', listOfFlightsById: [2]},
{id: 3, name: 'Ala', surname: 'maKota', gender: 'Male', country: 'Poland', birthDate: '19.03.1993', listOfFlightsById: [3]},
];
//addToDb(tourists, "tourists")
//db.tourists.insert({id: 1, name: 'Ala', surname: 'maKota', gender: 'Male', country: 'Poland', birthDate: '19.03.1993', listOfFlightsById: [1]})
const flights = [
{id:1, arrivalDate: {created: {type:Date, default:Date.now},}, departureDate: {created: {type:Date, default:Date.now},}, numberOfPlaces:15, touristsList: [""], price: "15$" },
{id:2, arrivalDate: {created: {type:Date, default:Date.now},}, departureDate: {created: {type:Date, default:Date.now},}, numberOfPlaces:15, touristsList: [""], price: "15$" },
{id:3, arrivalDate: {created: {type:Date, default:Date.now},}, departureDate: {created: {type:Date, default:Date.now},}, numberOfPlaces:15, touristsList: [""], price: "15$"},
];
//addToDb(flights, "flights")
//db.flights.insert({id:1, arrivalDate: {created: {type:Date, default:Date.now},}, departureDate: {created: {type:Date, default:Date.now},}, numberOfPlaces:15, touristsList: [""], price: "15$" })
app.get('/', (req, res) => {
});
app.get('/api/tourists', (req,res) => {
findAll("tourists", function(result) {
res.send(result)
})
});
app.post('/api/tourists', (req, res) => {
const tourist = [{
id: tourists.length + 1,
name: req.body.name,
surname: req.body.surname,
gender: req.body.gender,
country: req.body.country,
birthDate: req.body.birthDate,
listOfFlightsById: req.body.listOfFlightsById
},];
tourists.push(tourist);
addToDb(tourist, "tourists")
res.send(tourist);
});
app.get('/api/tourists/:id', (req,res) => {
const tourist = tourists.find(c => c.id === parseInt(req.params.id));
if (!tourist) return res.status(404).send('The tourist with given id do not exist');
else res.send(tourist);
});
//PORT:
const port = process.env.PORT || 3000;
app.listen(port, () => console.log(`Listen on port ${port} ...`));
app.put('/api/addFlightToTourist/:id/:idT', (req, res) => {
const tourist = tourists.find(c=> c.id === parseInt(req.params.idT))
if (!tourist) {
res.status(404).send('The tourist with given id do not exist');
return;
}
const flight = flights.find(c => c.id === parseInt(req.params.id));
if (!flight) {
res.status(404).send('The flight with given id do not exist');
return;
}
if (tourist.listOfFlightsById.includes(parseInt(req.params.id))) {
res.status(404).send('The tourist is already booked for this flight');
return;
}
else {
if(flights.find(c=>c.touristsList.length === c.numberOfPlaces)) {
res.send("Sorry, but flight is full, choose another flight id.")
return;
}
else {
tourist.listOfFlightsById.push(parseInt(req.params.id))
}
}
res.send(tourist);
})
app.delete('/api/tourists/:id', (req, res) => {
const tourist = tourists.find(c=> c.id === parseInt(req.params.id));
if (!tourist) return res.status(404).send("Invalid tourist id");
const index = tourists.indexOf(touristu);
tourists.splice(index,1);
res.send(tourists);
})
解决方案
就像@Chris G 在评论中所说的那样，您将返回您的toArray()功能而不是您的findAll()功能。你需要一个回调或一个承诺。你可以用回调做这样的事情
function findAll(collection, cb) {
var MongoClient = require('mongodb').MongoClient;
var url = "mongodb://localhost/";
MongoClient.connect(url, function(err, db, res) {
if (err) throw err;
var dbo = db.db("airport");
dbo.collection(collection).find({}).toArray(function(err, res, result) {
if (err) throw err;
cb(result)
});
db.close();
});
}
在您的网络应用程序代码中findAll，使用回调函数调用该函数并发送结果
app.get('/api/tourists', (req,res) => {
findAll("tourists", function(result) {
res.send(result)
}
});
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