尝试使用Delete时ERR

尝试创建一个API，我们可以使用CRUD选项。事情是我们的删除功能dosnt工作，当我们点击删除帖子后网站崩溃。

（填写信息导致stackoverflow不会让我发布这个愚蠢的事情。）

    var mongoose = require('mongoose');
    var express = require('express');
    var cors = require('cors');
    var bodyParser = require('body-parser');


     mongoose.connect("mongodb://localhost/shop");


    var Schema = mongoose.Schema;

    var productSchema = new Schema({
      id: String,
      name: String,
      description: String,
      origin: String,
      categories: [{type: Schema.Types.ObjectId, ref: "Category"}]
    }, {collection: 'product'});

    var categorySchema = new Schema({
     _id: Schema.Types.ObjectId,
      name: String,
      description: String,
      products: [{type: Schema.Types.ObjectId, ref: "Product"}]
    }, {collection: 'category'});

    var personSchema = new Schema({
        _id: Schema.Types.ObjectId,
         name: String,
         email: String,
         phone: String
       }, {collection: 'person'});

       var listSchema = new Schema({
        _id: Schema.Types.ObjectId,
         name: String,
         date: String,
         product: [String]
       }, {collection: 'list'});

    var Product = mongoose.model('Product', productSchema);
    var Category = mongoose.model('Category', categorySchema);
    var Person = mongoose.model('Person', personSchema);
    var List = mongoose.model('List', listSchema);


    var app = express();
    app.use(cors());
    app.use(bodyParser.json());
    app.use(bodyParser.urlencoded({ extended: true }));

    /* Get */

    app.get('/', function(req,res){
        Product.find({}, '', function(error, product){
            Person.find({},'', function(error, person){
                Category.find({},'', function(error, category){
                    List.find({},'', function(error, list){
                        res.json({
                            Product: product,
                            Person: person,
                            Category: category,
                            List: list
                        });
                    });
                });
            });
        });
    });



    app.post("/product", function(req, res) {
        var newItem = new Product (req.body);
        newItem.save()
            .then (function(product) {
                Category.findByIdAndUpdate(
                req.body.categories, { $push: {"products": product._id }}, { new: true }, function (err, product) {
                    res.send(product);
            })
            .catch (function(err) {
                res.status(400).send("unable to add item to db");
            });
        });
    });



    app.get('/all', function(req,res){
        Category.
            find({}).
            populate("products").
            exec(function (err, product) {
                res.json(product);
            });
    });

    app.get('/category/:id', function(req,res){
        Category.
            find({_id: mongoose.Types.ObjectId(req.params.id)}).
            populate("products").
            exec(function (err, product) {
                res.json(product);
            });
    });

    app.get('/category/1', function(req,res){
        Category.
            find({name: "grönsaker"}).
            populate("products").
            exec(function (err, product) {
                res.json(product);
            });
    });

    app.get('/category/2', function(req,res){
        Category.
            find({name: "mejeri"}).
            populate("products").
            exec(function (err, product) {
                res.json(product);
            });
    });










    app.put('/product/:id', function(req, res)  {
        Product.findByIdAndUpdate(req.params.id, { $set: req.body }, { new: true }, function (err, product) {
            if (err) return handleError(err);
            res.send(product);
          });
    });

    /

    app.delete('/product', function (req, res) {
        Category.findById(req.body._id, function (err, product) {
            var cat_id = Product.categories [0]
            Category.findByIdAndUpdate(cat_id, { $pull: {products: req.body._id}}, function(err, product){
                product.remove();
            });
        });
    });

    app.listen(3000);

我们知道SendDeleteRequest的ID有问题，但我们不知道应该写什么。

<!DOCTYPE html>
<html>
    <head>
        <title>Express.js client</title>
        <script src=".2.1/jquery.min.js"></script>
        <script>

        function sendGetRequest() {
        var data = { id: 123 };
        $.ajax({
            url: "http://localhost:3000/all",
            type: "GET",
            data: data,
            success: response => $("#response").text(JSON.stringify(response))
        }); 
        }

        function sendGetGronsaker() {
        var data = { id: "5a1696d69759edba95fa4b18" };
        $.ajax({
            url: "http://localhost:3000/category/5a1696d69759edba95fa4b18",
            type: "GET",
            data: data,
            success: response => $("#response").text(JSON.stringify(response))
        }); 
        }

        function sendGetMejeri() {
        var data = { id: "5a1696d69759edba95fa4b17" };
        $.ajax({
            url: "http://localhost:3000/category/5a1696d69759edba95fa4b17",
            type: "GET",
            data: data,
            success: response => $("#response").text(JSON.stringify(response))
        }); 
        }

        /* function sendGetGronsaker() {
        var data = { id: "5a1696d69759edba95fa4b18" };
        $.ajax({
            url: "http://localhost:3000/category/5a1696d69759edba95fa4b18",
            type: "GET",
            data: data,
            success: response => $("#response").text(JSON.stringify(response))
        }); 
        } */

        function sendPostRequest() {
            var data = { name: "majs", description: "Majs är gott", origin: "spain", categories: "5a1696d69759edba95fa4b18" };
            $.ajax({
                url: "http://localhost:3000/product",
                type: "POST",
                data: JSON.stringify(data),
                contentType: "application/json; charset=utf-8",
                success: response => $("#response").text(JSON.stringify(response))
            }); 
        }

        function sendPutRequest() { 
            var data = { origin: "spain" };
            $.ajax({
                url: "http://localhost:3000/product/5a1696d79759edba95fa4b20",
                type: "PUT",
                data: JSON.stringify(data),
                contentType: "application/json; charset=utf-8",
                success: response => $("#response").text(JSON.stringify(response))
            }); 
        }

        function sendDeleteRequest() {
            var data = { id: 789 };
            $.ajax({
                url: "http://localhost:3000/product",
                type: "DELETE",
                data: data,
                success: response => $("#response").text(response)
            }); 
        }
        </script>
        <style type="text/css">
        #output {
            margin-bottom: 3ex;
        }

        #label {
            font-weight: bold;
        }
        </style>
    </head>
    <body>
        <div id="output">
            <span id="label">Server response:</span>
            <span id="response"></span>
        </div>

        <div>
            <button onclick="sendGetMejeri()">GET Mejeri</button>
            <button onclick="sendGetGronsaker()">GET Gronsaker</button>
            <button onclick="sendGetRequest()">GET All</button>
            <button onclick="sendPostRequest()">Send POST request</button>
            <button onclick="sendPutRequest()">Send tomat PUT request</button>
            <button onclick="sendDeleteRequest()">Send DELETE request</button>
        </div>
    </body>
</html>

您正在传递id参数而没有下划线char

只需将req.body._id更改为req.body.id即可

app.delete('/product', function (req, res) {
    Category.findById(req.body.id, function (err, product) {
        var cat_id = Product.categories [0]
        Category.findByIdAndUpdate(cat_id, { $pull: {products: req.body.id}}, function(err, product){
            product.remove();
        });
    });
});

尝试使用Delete时ERR

尝试创建一个API，我们可以使用CRUD选项。事情是我们的删除功能dosnt工作，当我们点击删除帖子后网站崩溃。

（填写信息导致stackoverflow不会让我发布这个愚蠢的事情。）

    var mongoose = require('mongoose');
    var express = require('express');
    var cors = require('cors');
    var bodyParser = require('body-parser');


     mongoose.connect("mongodb://localhost/shop");


    var Schema = mongoose.Schema;

    var productSchema = new Schema({
      id: String,
      name: String,
      description: String,
      origin: String,
      categories: [{type: Schema.Types.ObjectId, ref: "Category"}]
    }, {collection: 'product'});

    var categorySchema = new Schema({
     _id: Schema.Types.ObjectId,
      name: String,
      description: String,
      products: [{type: Schema.Types.ObjectId, ref: "Product"}]
    }, {collection: 'category'});

    var personSchema = new Schema({
        _id: Schema.Types.ObjectId,
         name: String,
         email: String,
         phone: String
       }, {collection: 'person'});

       var listSchema = new Schema({
        _id: Schema.Types.ObjectId,
         name: String,
         date: String,
         product: [String]
       }, {collection: 'list'});

    var Product = mongoose.model('Product', productSchema);
    var Category = mongoose.model('Category', categorySchema);
    var Person = mongoose.model('Person', personSchema);
    var List = mongoose.model('List', listSchema);


    var app = express();
    app.use(cors());
    app.use(bodyParser.json());
    app.use(bodyParser.urlencoded({ extended: true }));

    /* Get */

    app.get('/', function(req,res){
        Product.find({}, '', function(error, product){
            Person.find({},'', function(error, person){
                Category.find({},'', function(error, category){
                    List.find({},'', function(error, list){
                        res.json({
                            Product: product,
                            Person: person,
                            Category: category,
                            List: list
                        });
                    });
                });
            });
        });
    });



    app.post("/product", function(req, res) {
        var newItem = new Product (req.body);
        newItem.save()
            .then (function(product) {
                Category.findByIdAndUpdate(
                req.body.categories, { $push: {"products": product._id }}, { new: true }, function (err, product) {
                    res.send(product);
            })
            .catch (function(err) {
                res.status(400).send("unable to add item to db");
            });
        });
    });



    app.get('/all', function(req,res){
        Category.
            find({}).
            populate("products").
            exec(function (err, product) {
                res.json(product);
            });
    });

    app.get('/category/:id', function(req,res){
        Category.
            find({_id: mongoose.Types.ObjectId(req.params.id)}).
            populate("products").
            exec(function (err, product) {
                res.json(product);
            });
    });

    app.get('/category/1', function(req,res){
        Category.
            find({name: "grönsaker"}).
            populate("products").
            exec(function (err, product) {
                res.json(product);
            });
    });

    app.get('/category/2', function(req,res){
        Category.
            find({name: "mejeri"}).
            populate("products").
            exec(function (err, product) {
                res.json(product);
            });
    });










    app.put('/product/:id', function(req, res)  {
        Product.findByIdAndUpdate(req.params.id, { $set: req.body }, { new: true }, function (err, product) {
            if (err) return handleError(err);
            res.send(product);
          });
    });

    /

    app.delete('/product', function (req, res) {
        Category.findById(req.body._id, function (err, product) {
            var cat_id = Product.categories [0]
            Category.findByIdAndUpdate(cat_id, { $pull: {products: req.body._id}}, function(err, product){
                product.remove();
            });
        });
    });

    app.listen(3000);

我们知道SendDeleteRequest的ID有问题，但我们不知道应该写什么。

<!DOCTYPE html>
<html>
    <head>
        <title>Express.js client</title>
        <script src=".2.1/jquery.min.js"></script>
        <script>

        function sendGetRequest() {
        var data = { id: 123 };
        $.ajax({
            url: "http://localhost:3000/all",
            type: "GET",
            data: data,
            success: response => $("#response").text(JSON.stringify(response))
        }); 
        }

        function sendGetGronsaker() {
        var data = { id: "5a1696d69759edba95fa4b18" };
        $.ajax({
            url: "http://localhost:3000/category/5a1696d69759edba95fa4b18",
            type: "GET",
            data: data,
            success: response => $("#response").text(JSON.stringify(response))
        }); 
        }

        function sendGetMejeri() {
        var data = { id: "5a1696d69759edba95fa4b17" };
        $.ajax({
            url: "http://localhost:3000/category/5a1696d69759edba95fa4b17",
            type: "GET",
            data: data,
            success: response => $("#response").text(JSON.stringify(response))
        }); 
        }

        /* function sendGetGronsaker() {
        var data = { id: "5a1696d69759edba95fa4b18" };
        $.ajax({
            url: "http://localhost:3000/category/5a1696d69759edba95fa4b18",
            type: "GET",
            data: data,
            success: response => $("#response").text(JSON.stringify(response))
        }); 
        } */

        function sendPostRequest() {
            var data = { name: "majs", description: "Majs är gott", origin: "spain", categories: "5a1696d69759edba95fa4b18" };
            $.ajax({
                url: "http://localhost:3000/product",
                type: "POST",
                data: JSON.stringify(data),
                contentType: "application/json; charset=utf-8",
                success: response => $("#response").text(JSON.stringify(response))
            }); 
        }

        function sendPutRequest() { 
            var data = { origin: "spain" };
            $.ajax({
                url: "http://localhost:3000/product/5a1696d79759edba95fa4b20",
                type: "PUT",
                data: JSON.stringify(data),
                contentType: "application/json; charset=utf-8",
                success: response => $("#response").text(JSON.stringify(response))
            }); 
        }

        function sendDeleteRequest() {
            var data = { id: 789 };
            $.ajax({
                url: "http://localhost:3000/product",
                type: "DELETE",
                data: data,
                success: response => $("#response").text(response)
            }); 
        }
        </script>
        <style type="text/css">
        #output {
            margin-bottom: 3ex;
        }

        #label {
            font-weight: bold;
        }
        </style>
    </head>
    <body>
        <div id="output">
            <span id="label">Server response:</span>
            <span id="response"></span>
        </div>

        <div>
            <button onclick="sendGetMejeri()">GET Mejeri</button>
            <button onclick="sendGetGronsaker()">GET Gronsaker</button>
            <button onclick="sendGetRequest()">GET All</button>
            <button onclick="sendPostRequest()">Send POST request</button>
            <button onclick="sendPutRequest()">Send tomat PUT request</button>
            <button onclick="sendDeleteRequest()">Send DELETE request</button>
        </div>
    </body>
</html>

您正在传递id参数而没有下划线char

只需将req.body._id更改为req.body.id即可

app.delete('/product', function (req, res) {
    Category.findById(req.body.id, function (err, product) {
        var cat_id = Product.categories [0]
        Category.findByIdAndUpdate(cat_id, { $pull: {products: req.body.id}}, function(err, product){
            product.remove();
        });
    });
});