Question

修改我的问题稍有改动，所以我更新了我的代码并修改了我的问题。一切似乎都在起作用，除非我没有在浏览器中看到我的JSON。

这是我目前的代码：

'use strict';
var util = require('util');
var http = require('http');
var sql = require("mssql");
var express = require('express')
var port = process.env.PORT || 1337;

var membershipNumber;
var results;
var queryString;

var app = express();

function getParams() {
    app.get('/:number', function (req, res) {
        console.log("\nPARAMS:");
        console.log(req.params.number);

        membershipNumber = req.params.number;
        queryString = util.format('SELECT major_key, status, paid_thru FROM name WHERE major_key = \'%s\' and member_record = 1', membershipNumber);
        console.log("\nQUERY:");
        console.log(queryString);

        res.setHeader('Content-Type', 'application/json');
        // res.end(queryDatabase(queryString));
        res.send(queryDatabase(queryString));
    });
    app.listen(port);
}

function queryDatabase(query) {
    var config = {
        server: 'testserver',
        database: 'test_db',
        user: 'sa',
        password: 'password',
        port: 1433
    };

    var connection = new sql.Connection(config);

    connection.connect().then(function () {
        var req = new sql.Request(connection);
        req.query(query).then(function (recordset) {
            results = recordset;
            console.log("\nRESULTS:");
            console.log(results);
            connection.close();

            //Convert results to JSON string
            var jsonString = JSON.stringify(results);
            console.log("\njsonString:");
            console.log(jsonString);

            return jsonString;

        })
            .catch(function (err) {
                console.log(err);
                connection.close();
            });
    })
        .catch(function (err) {
            console.log(err);
        });
}

getParams();

这就是我的console.log语句在控制台＆＃34;

中打印的内容

PARAMS:
0001354648

QUERY:
SELECT major_key, status, paid_thru FROM name WHERE major_key = '0001354648' and member_record = 1

RESULTS:
[ { major_key: '0001354648',
    status: 'SN',
    paid_thru: 2016-10-31T00:00:00.000Z } ]

jsonString:
[{"major_key":"0001354648","status":"SN","paid_thru":"2016-10-31T00:00:00.000Z"}]

Answer 1

您有两个app.listen()来电：一个在appFunction()，另一个在getParams()。您应该只调用app.listen()一次并删除appFunction()中的getParams()，因为function queryDatabase(query) { var config = { server: 'dbserver', database: 'test_db', user: 'sa', password: 'password', port: 1433 }; var connection = new sql.Connection(config); connection.connect().then(function() { var req = new sql.Request(connection); req.query(query).then(function(recordset) { results = recordset; console.log("\nRESULTS:"); console.log(results); connection.close(); //Convert results to JSON string jsonString = JSON.stringify(results); console.log("\nJSON:"); console.log(jsonString); appFunction(jsonString); }) .catch(function(err) { console.log(err); connection.close(); }); }) .catch(function(err) { console.log(err); }); } app.get('/:number', function(req, res) { console.log("\nPARAMS:"); console.log(req.params.number); membershipNumber = req.params.number; queryString = util.format('SELECT major_key, status, paid_thru FROM name WHERE major_key = \'%s\' and member_record = 1', membershipNumber); console.log("\nQUERY:"); console.log(queryString); res.end(queryDatabase(queryString)); }); app.get('/', function(req, res) { res.setHeader('Content-Type', 'application/json'); res.send(jsonString); }); app.listen(port);似乎是您在初始化时调用的函数。

如果您确实需要以这种方式构建代码，请尝试以下方法：

queryDatabase()

请注意，这一次只能处理一个请求。

我强烈建议在进行REST调用时将GET http://<your-ip>:<your-port>/3 RESPONSE: { some JSON }函数的输出返回给用户;在这种情况下，您的'/：number'路由将返回您想要接收的JSON字符串。在您的应用程序中，REST与此接口，您会看到以下内容：

// This function takes a file path and loads the data into a variable, then calls plot_data
    function load_file(file) {

        // removes previous SVG plots to prevent messy overlays and memory chaos
        d3.selectAll("svg").remove();

        // This code takes the file (which is a path, and puts it into var data, which is then given to the parcoords plot function)
        d3.text(file, function(text) {
            var data = d3.csv.parseRows(text).map(function(row) {
                return row.map(function(value) {
                    return +value;

                });
            });


// This function plots the data given to it.
    function plot_data(data) {

        pc1 = d3.parcoords()("#example")
                // This is how we get colour working. put a function in the parameters it iterates over each data item .color()
                .data(data)
                .render()
                .alpha(0.35)
                .brushMode("1D-axes")
                .interactive()  // command line mode


        pc1.reorderable();
        console.log("The plot should be done now")
    };

此时你不需要'/'路线。

Node.js数据库查询

1 个答案: