表达生成JSON [英] Express to generate JSON

问题描述

我尝试传递一个关键值，并根据传递的密钥生成JSON响应

Express Program

Express Program

var express = require('express'),
    async = require('async'),
    http = require('http'),
    mysql = require('mysql');

var app = express();

var connection = mysql.createConnection({
    host: 'localhost',
    user: 'root',
    password: "root",
    database: 'restaurants'
});

connection.connect();

// all environments
app.set('port', process.env.PORT || 7004);

app.get('/RestaurantDesc/', function (request, response, next) {

    var keyName = request.query.Key;
    var name_of_restaurants, RestaurantTimings;
    async.series([
        // Get the first table contents
        function (callback) {
            connection.query('SELECT * FROM ', keyName, function (err, rows, fields) {
                console.log('Connection result error ' + err);
                name_of_restaurants = rows;
                callback();
            });
        },
        // Get the second table contents
        function (callback) {
            connection.query('SELECT * FROM RestaurantTimings', function (err, rows, fields)

            {
                console.log('Connection result error ' + err);
                RestaurantTimings = rows;
                callback();
            });
        }
    // Send the response
    ], function (error, results) {
        response.json({
            'restaurants': name_of_restaurants,
                'RestaurantTimings': RestaurantTimings
        });
    });
});

app.get('/RestaurantDesc/', function (request, response, next) {

    var keyName = request.query.Key;
    var name_of_restaurants, RestaurantTimings;
    async.series([
    // Get the first table contents
    function (callback) {
        connection.query('SELECT * FROM ', keyName, function (err, rows, fields) {
            console.log('Connection result error ' + err);
            name_of_restaurants = rows;
            callback();
        });
    },
    // Get the second table contents
    function (callback) {
        connection.query('SELECT * FROM RestaurantTimings', function (err, rows, fields)

        {
            console.log('Connection result error ' + err);
            RestaurantTimings = rows;
            callback();
        });
    }

    // Send the response
    ], function (error, results) {
        response.json({
            'restaurants': name_of_restaurants,
                'RestaurantTimings': RestaurantTimings
        });
    });
});

http.createServer(app).listen(app.get('port'), function () {
    console.log('Express server listening on port ' + app.get('port'));
});

测试运行::

我收到了RestaurantTimings的JSON响应，但不是通过keyvalue的第一个响应，如何解决这个问题？

推荐答案

您有两个处理程序路径 / RestaurantDesc / - 只有一个应该保留。

You have two handlers for the path /RestaurantDesc/ - only one should be kept.

在您的查询中，语法错误。

In your query, the syntax is wrong.

假设您有一个看起来像这样的表（更改这些名称以匹配您的模式）：

Assuming you have a table that looks like this (change these names to match your schema):

Table Name: Restaurant
    column:       name

而您正在使用 node-mysql ，将查询更改为这个：

And you are using node-mysql, Change your query to something like this:

connection.query('SELECT * FROM Restaurant where name = ?', [keyName], function (err, rows, fields) {
    console.log('Connection result error ' + err);
    name_of_restaurants = rows;
    callback();
});

是在第二个参数中传递给查询的值的数组中传递的值的占位符。

The ? is a place holder for values passed in the array of values passed in the second parameter to query.

请参阅：转义查询值以获取有关如何工作的更多信息。简单的答案是，使用这种方法可以正确地转义这些值。

See: Escaping query values for more information on how this works. Short answer though is that the values will be escaped properly using this approach.

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