试图将我的 node.js 连接到 Heroku PostgreSQL 数据库.遵循 Heroku Postgres 教程

本文介绍了试图将我的 node.js 连接到 Heroku PostgreSQL 数据库.遵循 Heroku Postgres 教程的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我正在关注这两个 Heroku 教程:

I'm following these two Heroku tutorials:

devcenter.heroku/articles/getting-started-with-nodejs

和

devcenter.heroku/articles/heroku-postgresql

我可以使用hello world"应用程序.但是当我添加 node.js 代码以连接到 postgreSQL 时出现错误.

I have the 'hello world' app working. But I am getting an error when I add the node.js code to connect to postgreSQL.

我的 package.json

My package.json

{ "name": "node-example", "version": "0.0.1", "dependencies": { "pg": "2.x", "express": "3.1.x" }, "engines": { "node": "0.10.x", "npm": "1.2.x" } }

我的 web.js

var express = require("express"); var app = express(); app.use(express.logger()); app.get('/', function(request, response) { response.send('Hello World!'); }); var port = process.env.PORT || 5000; app.listen(port, function() { console.log("Listening on " + port); }); var pg = require('pg'); pg.connect(process.env.DATABASE_URL, function(err, client, done) { client.query('SELECT * FROM your_table', function(err, result) { done(); if(err) return console.error(err); console.log(result.rows); }); });

我的 Heroku postgres 数据库运行良好，我可以使用

My Heroku postgres database is working well and I can connect to it directly with

heroku pg:psql

这是我的日志:

2013-09-29T13:13:34.777156+00:00 heroku[web.1]: State changed from starting to up 2013-09-29T13:13:34.784018+00:00 app[web.1]: 2013-09-29T13:13:34.787193+00:00 app[web.1]: events.js:72 2013-09-29T13:13:34.787469+00:00 app[web.1]: throw er; // Unhandled 'error' event 2013-09-29T13:13:34.787642+00:00 app[web.1]: ^ 2013-09-29T13:13:34.790791+00:00 app[web.1]: error: relation "junk" does not exist 2013-09-29T13:13:34.790791+00:00 app[web.1]: at Connection.parseE (/app/node_modules/pg/lib/connection.js:546:11) 2013-09-29T13:13:34.790791+00:00 app[web.1]: at Connection.parseMessage (/app/node_modules/pg/lib/connection.js:375:17) 2013-09-29T13:13:34.790791+00:00 app[web.1]: at null.<anonymous> (/app/node_modules/pg/lib/connection.js:92:20) 2013-09-29T13:13:34.790791+00:00 app[web.1]: at Socket.EventEmitter.emit (events.js:95:17) 2013-09-29T13:13:34.790791+00:00 app[web.1]: at Socket.<anonymous> (_stream_readable.js:746:14) 2013-09-29T13:13:34.790791+00:00 app[web.1]: at Socket.EventEmitter.emit (events.js:92:17) 2013-09-29T13:13:34.790791+00:00 app[web.1]: at emitReadable_ (_stream_readable.js:408:10) 2013-09-29T13:13:34.790791+00:00 app[web.1]: at emitReadable (_stream_readable.js:404:5) 2013-09-29T13:13:34.790791+00:00 app[web.1]: at readableAddChunk (_stream_readable.js:165:9) 2013-09-29T13:13:34.790968+00:00 app[web.1]: at Socket.Readable.push (_stream_readable.js:127:10) 2013-09-29T13:13:36.511975+00:00 heroku[web.1]: Process exited with status 8 2013-09-29T13:13:36.527681+00:00 heroku[web.1]: State changed from up to crashed 2013-09-29T13:21:22+00:00 heroku[slug-compiler]: Slug compilation started 2013-09-29T13:21:38+00:00 heroku[slug-compiler]: Slug compilation finished 2013-09-29T13:21:39.239935+00:00 heroku[web.1]: State changed from crashed to starting 2013-09-29T13:21:40.589773+00:00 heroku[web.1]: Starting process with command `node web.js` 2013-09-29T13:21:41.345806+00:00 app[web.1]: Listening on 20977 2013-09-29T13:21:41.368323+00:00 app[web.1]: { [error: relation "your_table" does not exist] 2013-09-29T13:21:41.368323+00:00 app[web.1]: length: 101, 2013-09-29T13:21:41.368323+00:00 app[web.1]: detail: undefined, 2013-09-29T13:21:41.368323+00:00 app[web.1]: severity: 'ERROR', 2013-09-29T13:21:41.368323+00:00 app[web.1]: hint: undefined, 2013-09-29T13:21:41.368323+00:00 app[web.1]: position: '15', 2013-09-29T13:21:41.368323+00:00 app[web.1]: code: '42P01', 2013-09-29T13:21:41.368323+00:00 app[web.1]: name: 'error', 2013-09-29T13:21:41.368323+00:00 app[web.1]: internalPosition: undefined, 2013-09-29T13:21:41.368512+00:00 app[web.1]: where: undefined, 2013-09-29T13:21:41.368512+00:00 app[web.1]: file: 'parse_relation.c', 2013-09-29T13:21:41.368512+00:00 app[web.1]: line: '864', 2013-09-29T13:21:41.368323+00:00 app[web.1]: internalQuery: undefined, 2013-09-29T13:21:41.368512+00:00 app[web.1]: routine: 'parserOpenTable' } 2013-09-29T13:21:41.938926+00:00 heroku[web.1]: State changed from starting to up 2013-09-29T13:21:38.600520+00:00 heroku[api]: Deploy 95a0a35 by *********@gmail 2013-09-29T13:21:38.625733+00:00 heroku[api]: Release v17 created by *******@gmail 2013-09-29T13:22:08.383050+00:00 heroku[router]: at=info method=GET path=/ host=pure-lake-7106.herokuapp fwd="58.7.243.156" dyno=web.1 connect=3ms service=6ms status=200 bytes=12 2013-09-29T13:22:08.383327+00:00 app[web.1]: - - - [Sun, 29 Sep 2013 13:22:08 GMT] "GET / HTTP/1.1" 200 12 "-" "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Ubuntu Chromium/28.0.1500.71 Chrome/28.0.1500.71 Safari/537.36" 2013-09-29T13:22:10.046808+00:00 app[web.1]: - - - [Sun, 29 Sep 2013 13:22:10 GMT] "GET /favicon.ico HTTP/1.1" 404 - "-" "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Ubuntu Chromium/28.0.1500.71 Chrome/28.0.1500.71 Safari/537.36" 2013-09-29T13:22:10.049179+00:00 heroku[router]: at=info method=GET path=/favicon.ico host=pure-lake-7106.herokuapp fwd="58.7.243.156" dyno=web.1 connect=1ms service=3ms status=404 bytes=34 2013-09-29T13:29:40+00:00 heroku[slug-compiler]: Slug compilation started 2013-09-29T13:30:07.484077+00:00 heroku[api]: Deploy a2cc795 by xxxxxxxxxxx@gmail 2013-09-29T13:30:07.515481+00:00 heroku[api]: Release v18 created by xxxxxxxxx@gmail 2013-09-29T13:30:07+00:00 heroku[slug-compiler]: Slug compilation finished 2013-09-29T13:30:08.016355+00:00 heroku[web.1]: State changed from up to starting 2013-09-29T13:30:10.017792+00:00 heroku[web.1]: Starting process with command `node web.js` 2013-09-29T13:30:10.099473+00:00 heroku[web.1]: Stopping all processes with SIGTERM 2013-09-29T13:30:11.008770+00:00 app[web.1]: Listening on 47344 2013-09-29T13:30:11.065531+00:00 app[web.1]: name: 'error', 2013-09-29T13:30:11.065531+00:00 app[web.1]: length: 101, 2013-09-29T13:30:11.065531+00:00 app[web.1]: severity: 'ERROR', 2013-09-29T13:30:11.065531+00:00 app[web.1]: code: '42P01', 2013-09-29T13:30:11.065531+00:00 app[web.1]: detail: undefined, 2013-09-29T13:30:11.065531+00:00 app[web.1]: position: '15', 2013-09-29T13:30:11.065531+00:00 app[web.1]: { [error: relation "your_table" does not exist] 2013-09-29T13:30:11.065531+00:00 app[web.1]: internalPosition: undefined, 2013-09-29T13:30:11.065531+00:00 app[web.1]: internalQuery: undefined, 2013-09-29T13:30:11.065840+00:00 app[web.1]: where: undefined, 2013-09-29T13:30:11.065840+00:00 app[web.1]: file: 'parse_relation.c', 2013-09-29T13:30:11.065840+00:00 app[web.1]: line: '864', 2013-09-29T13:30:11.065840+00:00 app[web.1]: routine: 'parserOpenTable' } 2013-09-29T13:30:11.065531+00:00 app[web.1]: hint: undefined, 2013-09-29T13:30:11.482704+00:00 heroku[web.1]: State changed from starting to up 2013-09-29T13:30:11.651117+00:00 heroku[web.1]: Process exited with status 143 2013-09-29T13:30:17.729604+00:00 app[web.1]: - - - [Sun, 29 Sep 2013 13:30:17 GMT] "GET / HTTP/1.1" 200 12 "-" "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Ubuntu Chromium/28.0.1500.71 Chrome/28.0.1500.71 Safari/537.36" 2013-09-29T13:30:19.361615+00:00 heroku[router]: at=info method=GET path=/favicon.ico host=pure-lake-7106.herokuapp fwd="58.7.243.156" dyno=web.1 connect=1ms service=3ms status=404 bytes=34 2013-09-29T13:30:19.364457+00:00 app[web.1]: - - - [Sun, 29 Sep 2013 13:30:19 GMT] "GET /favicon.ico HTTP/1.1" 404 - "-" "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Ubuntu Chromium/28.0.1500.71 Chrome/28.0.1500.71 Safari/537.36" 2013-09-29T13:30:17.728815+00:00 heroku[router]: at=info method=GET path=/ host=pure-lake-7106.herokuapp fwd="58.7.243.156" dyno=web.1 connect=1ms service=19ms status=200 bytes=12 2013-09-29T13:32:28+00:00 heroku[slug-compiler]: Slug compilation started 2013-09-29T13:32:43.338858+00:00 heroku[api]: Deploy d4cf2ba by xxxxxxxx@gmail 2013-09-29T13:32:43.359317+00:00 heroku[api]: Release v19 created by xxxxxxxx@gmail 2013-09-29T13:32:43+00:00 heroku[slug-compiler]: Slug compilation finished 2013-09-29T13:32:43.746015+00:00 heroku[web.1]: State changed from up to starting 2013-09-29T13:32:45.354842+00:00 heroku[web.1]: Starting process with command `node web.js` 2013-09-29T13:32:46.098651+00:00 app[web.1]: Listening on 37156 2013-09-29T13:32:47.127328+00:00 app[web.1]: { [error: relation "your_table" does not exist] 2013-09-29T13:32:47.127328+00:00 app[web.1]: code: '42P01', 2013-09-29T13:32:47.127328+00:00 app[web.1]: name: 'error', 2013-09-29T13:32:47.127328+00:00 app[web.1]: length: 101, 2013-09-29T13:32:47.127328+00:00 app[web.1]: hint: undefined, 2013-09-29T13:32:47.127328+00:00 app[web.1]: position: '15', 2013-09-29T13:32:47.127328+00:00 app[web.1]: severity: 'ERROR', 2013-09-29T13:32:47.127328+00:00 app[web.1]: detail: undefined, 2013-09-29T13:32:47.127561+00:00 app[web.1]: where: undefined, 2013-09-29T13:32:47.127561+00:00 app[web.1]: routine: 'parserOpenTable' } 2013-09-29T13:32:47.127328+00:00 app[web.1]: internalPosition: undefined, 2013-09-29T13:32:47.127328+00:00 app[web.1]: internalQuery: undefined, 2013-09-29T13:32:47.127561+00:00 app[web.1]: file: 'parse_relation.c', 2013-09-29T13:32:47.127561+00:00 app[web.1]: line: '864', 2013-09-29T13:32:47.197293+00:00 heroku[web.1]: State changed from starting to up 2013-09-29T13:32:50.505267+00:00 heroku[web.1]: Stopping all processes with SIGTERM 2013-09-29T13:32:53.246120+00:00 heroku[web.1]: Process exited with status 143 2013-09-29T14:39:50.833246+00:00 heroku[web.1]: Idling 2013-09-29T14:39:52.828292+00:00 heroku[web.1]: Stopping all processes with SIGTERM 2013-09-29T14:39:54.545662+00:00 heroku[web.1]: Process exited with status 143 2013-09-29T14:39:54.559151+00:00 heroku[web.1]: State changed from up to down

当我做工头开始时，我犯了这个错误

I get this erroe when I do a foreman start

p$ foreman start 12:39:41 web.1 | started with pid 13983 12:39:41 web.1 | Listening on 5000 12:39:41 web.1 | /home/roland/github/heroku_app/web.js:18 12:39:41 web.1 | client.query('SELECT * FROM your_table', function(err, result) { 12:39:41 web.1 | ^ 12:39:41 web.1 | TypeError: Cannot call method 'query' of null 12:39:41 web.1 | at /home/roland/github/heroku_app/web.js:18:10 12:39:41 web.1 | at /home/roland/github/heroku_app/node_modules/pg/lib/pool.js:54:25 12:39:41 web.1 | at /home/roland/github/heroku_app/node_modules/pg/node_modules/generic-pool/lib/generic-pool.js:271:11 12:39:41 web.1 | at /home/roland/github/heroku_app/node_modules/pg/lib/pool.js:27:26 12:39:41 web.1 | at null.<anonymous> (/home/roland/github/heroku_app/node_modules/pg/lib/client.js:169:9) 12:39:41 web.1 | at EventEmitter.emit (events.js:95:17) 12:39:41 web.1 | at null.<anonymous> (/home/roland/github/heroku_app/node_modules/pg/lib/connection.js:97:12) 12:39:41 web.1 | at Socket.EventEmitter.emit (events.js:95:17) 12:39:41 web.1 | at Socket.<anonymous> (_stream_readable.js:746:14) 12:39:41 web.1 | at Socket.EventEmitter.emit (events.js:92:17) 12:39:41 web.1 | exited with code 8 12:39:41 system | sending SIGTERM to all processes SIGTERM received

编辑我的 console.logs;

EDIT my console.logs;

var express = require("express"); var app = express(); app.use(express.logger()); app.get('/', function(request, response) { response.send('Hello World!'); console.log("hello roland"); }); var port = process.env.PORT || 5000; app.listen(port, function() { console.log("Listening on " + port); }); var pg = require('pg'); pg.connect(process.env.DATABASE_URL, function(err, client, done) { console.log(err+"!!!!!!!!!!!!!!!"); client.query('SELECT * FROM your_table', function(err, result) { done(); if(err) return console.error(err); console.log(result.rows); }); });

推荐答案

这是 Heroku 的问题.他们告诉您在 pg.connect 中使用的process.env.DATABASE_URL"变量不起作用.

It's Heroku's problem. The "process.env.DATABASE_URL" variable they tell you to use in pg.connect is not functioning.

简单的

console.log(process.env.DATABASE_URL);

将显示该变量未定义.

在 Heroku 提供修复之前，您可以将连接 URL 硬编码为 pg.connect() 的第一个参数.

Until Heroku offers a fix, you can hard-code the connection URL as the first argument to pg.connect().

要查找您的凭据，您可以通过 heroku.

To find your credentials, you can go to your app's PostgreSQL add-on connection settings through heroku.

新的 pg.connect 方法看起来像

The new pg.connect method will look like

var connectionString = "postgres://*USERNAME*:*PASSWORD*@*HOST*:*PORT*/*DATABASE*" pg.connect(connectionString, function(err, client, done) { client.query('SELECT * FROM your_table', function(err, result) { done(); if(err) return console.error(err); console.log(result.rows); }); });