Question

我使用nodejs作为我的REST api主机。整体功能非常基础。也就是说，进行REST调用，该调用应该执行postgres db查询并返回数据。我遇到的问题是整个代码组织。

我有一个基本初始化的server.js。现在，我应该在哪里放置postgres连接并在需要时调用它来查询db。目前的结构如下。所以我想我应该将postgres连接代码移动到server.js？什么应该是正确的结构

server.js

"use strict";

 var express = require('express'),
  app = express(),
  port = process.env.PORT || 4001,
  bodyParser = require('body-parser');

  app.use(bodyParser.urlencoded({ extended: true }));
  app.use(bodyParser.json());
  app.use(function (req, res, next) {

    // Website you wish to allow to connect
    res.setHeader('Access-Control-Allow-Origin', '*')
    // Request methods you wish to allow
    res.setHeader('Access-Control-Allow-Methods', 'GET, POST, OPTIONS, PUT, PATCH, DELETE');
    // Request headers you wish to allow
    res.setHeader('Access-Control-Allow-Headers', 'X-Requested-With,content-type');
    // Set to true if you need the website to include cookies in the requests sent
    // to the API (e.g. in case you use sessions)
    res.setHeader('Access-Control-Allow-Credentials', true);
    // Pass to next layer of middleware
    next();
});
var routes = require('./api/routes/pushRoutes');
routes(app);

app.listen(port);
console.log('push notification server started on: ' + port);

pushController.js

'use strict';

exports.send_notification = function(req, res) {
    console.log("start of send_notification ");

     if (req.method == 'POST') {
        var jsonString = '';

        req.on('data', function (data) {
            jsonString += data;
        });

        req.on('end', function () {
            console.log(JSON.parse(jsonString));
            var json = JSON.parse(jsonString);
            var timeNow = json.message;

            //get device token from db
            var deviceToken = '';
            var pg = require('pg')
            var format = require('pg-format')
            var PGUSER = 'deploy'
            var PGDATABASE = 'oscpushserver'
            var config = {
              user: PGUSER, // name of the user account
              database: PGDATABASE, // name of the database
              max: 10, // max number of clients in the pool
              idleTimeoutMillis: 30000 
            }

            var pool = new pg.Pool(config)
            var myClient

            pool.connect(function (err, client, done) {
              if (err) console.log(err)
              app.listen(3000, function () {
                console.log('listening on 3000')
              })
              myClient = client
              var ageQuery = format('SELECT * from push_table WHERE seq_id = 1')
              myClient.query(ageQuery, function (err, result) {
                if (err) {
                  console.log(err)
                }
                console.log("row data:" + result.rows[0])
                console.log("device id from db:" + result.rows[0].device_id)
                deviceToken =result.rows[0].device_id;


              })
            });


            res.json(JSON.parse(jsonString));
        });
    }

};

Answer 1

我假设你想制作一个只从db获取数据的REST API。

<强> server.js

在大多数部分看起来很好，除了你没有正确使用路线。要使用您定义的路线，请使用app.use：

app.use('/', routes);

<强> database.js 我会创建另一个文件，您可以将数据库凭据放在一个位置并创建一个新池。

var pg = require('pg')
var PGUSER = 'deploy'
var PGDATABASE = 'oscpushserver'
var config = {
  user: PGUSER, // name of the user account
  database: PGDATABASE, // name of the database
  max: 10, // max number of clients in the pool
  idleTimeoutMillis: 30000 
}

var pool = new pg.Pool(config);

module.exports = pool;

<强> pushController

我假设您要在server.js中要求此文件。因此，请确保路径指向'... / pushController'而不是'./api/routes/pushRoutes'。

const express = require('express');
const router = express.Router();
const format = require('pg-format');
const pool = require('../path/to/database.js');

router.get(function(req, res, next) {
  pool.connect(function (err, client, done) {
    if (err) throw new Error(err);
    var ageQuery = format('SELECT * from push_table WHERE seq_id = 1')
    client.query(ageQuery, function (err, result) {
      if (err) throw new Error(err);
      res.json(result.rows[0]); 
    })
  }); 
});

module.exports = router;

现在，对API服务器的GET请求应该从postgres数据库返回一个json对象。

有大量关于如何使用node和postgres制作REST API的示例。其中之一是：https://github.com/mjhea0/node-postgres-todo。

使用带有nodejs的postgres用于连接池

1 个答案: