I am trying to connect oracle with NodeJS. Steps followed as below. Pre - requisites there is no client installed except NodeJS(0.10.25) and npm(1.3.24).
In my ExpressJS Project:
npm install db-oracle
There is no error found while installing.
In app.js
var oracle = require('db-oracle');
var connString = "(DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=xxxx)(PORT=1521))(CONNECT_DATA=(SERVER=DEDICATED)(SERVICE_NAME=xxxx)))";
var connectData = { "tns": connString, "user": "XPPS_OWNER", "password": "Ex3ec" };
In one of the endpoint i coded like this,
app.get('/oracleendpoint',function(req,res){
connectData.connect(function(error) {
if (error) {
return console.log("CONNECTION ERROR: " + error);
}
this.query().select('*').from('Users').execute(function(error, rows) {
if (error) {
return console.log('ERROR: ' + error);
}
console.log(rows.length + ' ROWS');
});
});
});
Expected output is to connect the DB.
FYI: DB Instance is running fine.
Query:
What is the DB Name?
It is showing an error which show below. what would be root cause for this?
module.js:340
throw err;
^
Error: Cannot find module './build/Release/oracle_bindings'
at Function.Module._resolveFilename (module.js:338:15)
at Function.Module._load (module.js:280:25)
at Module.require (module.js:364:17)
at require (module.js:380:17)
at Object.<anonymous>
(C:\xampp\htdocs\mytest\node_modules\db-oracle\db-oracle.js:18:15)
at Module._compile (module.js:456:26)
at Object.Module._extensions..js (module.js:474:10)
at Module.load (module.js:356:32)
at Function.Module._load (module.js:312:12)
at Module.require (module.js:364:17)
Please let me know any missing or Installation required or any node modules required or code changes. I have Googled but in vain. Haven't found proper document for this error.
Oracle themselves have just released an Oracle driver for node.js: https://blogs.oracle.com/opal/entry/introducing_node_oracledb_a_node
Looks promising.
In your example, you use db-oracle module, I would recommend to use node-oracle module instead, as it is more popular/better maintained.
To connect to Oracle DB from Node, you have to follow the instructions on the page mentioned above.
Related
I am new on nodejs
ı have a project for server sent events.
I am trying get datas with server sent events on console.
this is my code:
var source = new EventSource('https://sse.now.sh');
source.onmessage = function(e) {
console.log(e.data)
};
but when i try start project with node file.js :
ReferenceError: EventSource is not defined
at Object.<anonymous> (c:\Users\SYDNEY\Desktop\server-sent-events-demo\src\client\js\app.js:7:5)
at Module._compile (internal/modules/cjs/loader.js:953:14)
at Object.Module._extensions..js (internal/modules/cjs/loader.js:973:10)
at Module.load (internal/modules/cjs/loader.js:812:32)
at Function.Module._load (internal/modules/cjs/loader.js:724:14)
at Function.Module.runMain (internal/modules/cjs/loader.js:1025:10)
at internal/main/run_main_module.js:17:11
its just simple but i couldnt do anyting. should ı download anything about that ? bcz this script working on jsbin(website)
I solved this problem with add top of codes
var EventSource = require('eventsource')
var source = new EventSource('https://sse.now.sh');
source.onmessage = function(e) {
console.log(e.data)
};
I deploy a node application to the Azure website.
The tricky part is that I'm using a node module called "opencv" that needs to be compiled at install time using node-gyp.
I use the node-gyp rebuild --arch=ia32 command to compile it int the windows10. But when I used it in the Azure website， I get following problem:
Wed Apr 26 2017 04:48:35 GMT+0000 (Coordinated Universal Time): Application has thrown an uncaught exception and is terminated:
Error: The specified module could not be found.
\\?\D:\home\site\wwwroot\app\api\lib\opencv.node
at Error (native)
at Object.Module._extensions..node (module.js:434:18)
at Module.load (module.js:343:32)
at Function.Module._load (module.js:300:12)
at Module.require (module.js:353:17)
at require (internal/module.js:12:17)
at Object.<anonymous> (D:\home\site\wwwroot\app\api\lib\image_operation.js:5:14)
at Module._compile (module.js:409:26)
at Object.Module._extensions..js (module.js:416:10)
at Module.load (module.js:343:32)
This is the code I call：
'use strict';
var fs = require('fs');
var path = require('path');
var opencv = require("./opencv.node");
function isContains(str, substr) {
return new RegExp(substr).test(str);
}
module.exports = {
post: function (imageInfo, data) {
if (isContains(imageInfo.imageName, ".yuv")) {
var imageName = imageInfo.imageName.substr(0, imageInfo.imageName.length - 3) + "jpg";
opencv.yuvToJpeg(path.resolve(__dirname, "../../image/" + imageName), imageInfo.width, imageInfo.height, Array.prototype.slice.call(data, 0));
} else if (isContains(imageInfo.imageName, ".jpg")) {
fs.writeFileSync(path.resolve(__dirname, "../../image/" + imageInfo.imageName), data);
}
return "success";
}
};
But that file is in-fact deployed on the server:
Please help me, and tell me what to do
Its readme says that "You'll need OpenCV 2.3.1 or newer installed before installing node-opencv". And as Azure Web Apps is a Software as a service (SaaS), we don't have the privilege to install arbitrary software there. But if that is a requirement for you, you'll need to use an alternative offering, like Cloud Service or VM.
Hey so I'm trying to get Nodejs Koa to talk to postgres using the Koa-pg module, but I keep getting a 'Can't find module pg' error.
I've tried to follow the koa-pg examples, but have come up short...so any advice would on how to progress would be appreciated.
If created my app.js file as follows:
var koa = require('koa');
var route = require('koa-route');
var koaPg = require('koa-pg');
var roads = require('./controllers/roads');
var app = module.exports = koa();
app.use(route.get('/roads/bbox/', roads.bbox));
app.listen(3000);
console.log('listening on port 3000');
And then created my controller file as follows:
var credentials = require('../credentials.js');
var environment = credentials.dev;
app.use(koaPg('postgres://' + environment.user + '#' + environment.host + ':' + environment.port + '/' + environment.database))
module.exports.bbox = function * bbox(next) {
var result = yield this.koaPg.db.client.queryPromise('SELECT now()')
console.log('result: ', result)
this.body = result.rows[0].now.toISOString()
};
But I'm getting the following error:
module.js:338
throw err;
^
Error: Cannot find module 'pg'
at Function.Module._resolveFilename (module.js:336:15)
at Function.Module._load (module.js:278:25)
at Module.require (module.js:365:17)
at require (module.js:384:17)
at Object.<anonymous> (c:\Users\User\Documents\restful_koa\node_modul
es\koa-pg\index.js:12:27)
at Module._compile (module.js:460:26)
at Object.Module._extensions..js (module.js:478:10)
at Module.load (module.js:355:32)
at Function.Module._load (module.js:310:12)
at Module.require (module.js:365:17)
This is only a personal project but I'd love to understand where i'm going wrong.
Cheers
As mentioned in the comments:
You need to install the pg module via npm install pg or npm install pg --save if you want to save it to package.json.
The reason you need to do this is koa-pg has co-pg as a dependency so when you install the former the latter is also installed. But pg is not a dependency of co-pg and that is why you have to install it separately.
Ok so node.js has been driving me crazy. I have been trying to run the exact same code from the book. But it throwing me an error. The code is simple and watches a file for changes
const fs= require('fs');
fs.watch('target.txt', function() {
console.log("File 'target.txt' just changed!");
});
console.log("Now watching target.txt for changes");
the js file for the code and text.txt is in the same dir. And I get this error
$ node --harmony watcher.js
fs.js:1051
throw errnoException(process._errno, 'watch');
^
Error: watch ENOENT
at errnoException (fs.js:1019:11)
at FSWatcher.start (fs.js:1051:11)
at Object.fs.watch (fs.js:1076:11)
at Object.<anonymous> (C:\cygwin64\home\Sinan\try\watcher.js:5:5)
at Module._compile (module.js:456:26)
at Object.Module._extensions..js (module.js:474:10)
at Module.load (module.js:356:32)
at Function.Module._load (module.js:312:12)
at Function.Module.runMain (module.js:497:10)
at startup (node.js:119:16)
Thanks beforehand.
I would also appropriate an uptodate source for learning node, I have tried 2 books and I can not even run example codes
I removed .txt extension and it worked.
fs.watch('target', function () {
console.log("File target.txt just changed");
});
After migrating my application from IntoVPS to Digital Ocean, my application crashes when it tries to upload photos to AWS S3.
The differences between the servers are: IntoVPS was running Ubuntu 10.10, and Digital Ocean is running Debian; IntoVPS had node 0.8.x, and Digital Ocean has 0.10.26.
There are no firewalls on the new server that could be causing this issue (I've checked).
The crash errors are:
Error: read ECONNRESET
at errnoException (net.js:904:11)
at Pipe.onread (net.js:558:19)
Error: spawn ENOENT
at errnoException (child_process.js:988:11)
at Process.ChildProcess._handle.onexit (child_process.js:779:34)
Error: write EPIPE
at errnoException (net.js:904:11)
at Object.afterWrite (net.js:720:19)
Some of these might be related to forever trying to restart the process (I figured that's what spawn might mean). The one I'd focus on is the ECONNRESET one.
So, I'm running my process using forever, and I'm using the knox module to connect to S3.
After googling I found: https://github.com/LearnBoost/knox/issues/198
I tried adding res.resume() to the callback of putFile like it says in the, but nothing changes; I still get the ECONNRESET error.
I've spent an entire day (yesterday) trying to fix this issue, and I can't continue having my production application be broken, so I decided to try switching to an older version of Node in order to temporarily (but quickly) fix this issue. So, I installed the n module to try and get 0.8.26 as the node version installed. Unfortunately, n didn't work, and here's the issue I created on that: https://github.com/visionmedia/n/issues/170
EDIT:
After exiting my ssh session and opening a new one, n is working. However, switching to 0.8.26 version of node causes another errors:
/apps/Foobar/node_modules/dnode/node_modules/weak/node_modules/bindings/bindings.js:83
throw e
^
Error: Module version mismatch, refusing to load.
at Object.Module._extensions..node (module.js:485:11)
at Module.load (module.js:356:32)
at Function.Module._load (module.js:312:12)
at Module.require (module.js:362:17)
at require (module.js:378:17)
at bindings (/apps/Foobar/node_modules/dnode/node_modules/weak/node_modules/bindings/bindings.js:76:44)
at Object.<anonymous> (/apps/Foobar/node_modules/dnode/node_modules/weak/lib/weak.js:1:97)
at Module._compile (module.js:449:26)
at Object.Module._extensions..js (module.js:467:10)
at Module.load (module.js:356:32)
at Function.Module._load (module.js:312:12)
at Module.require (module.js:362:17)
at require (module.js:378:17)
at Object.<anonymous> (/apps/Foobar/node_modules/dnode/index.js:5:12)
at Module._compile (module.js:449:26)
at Object.Module._extensions..js (module.js:467:10)
at Module.load (module.js:356:32)
at Function.Module._load (module.js:312:12)
at Module.require (module.js:362:17)
at require (module.js:378:17)
at Object.<anonymous> (/apps/Foobar/controllers/sock.js:2:13)
at Module._compile (module.js:449:26)
at Object.Module._extensions..js (module.js:467:10)
at Module.load (module.js:356:32)
at Function.Module._load (module.js:312:12)
at Module.require (module.js:362:17)
at require (module.js:378:17)
at global.Controller (/apps/Foobar/globals.js:2:9)
at Object.<anonymous> (/apps/Foobar/controllers/generosity.js:209:12)
at Module._compile (module.js:449:26)
at Object.Module._extensions..js (module.js:467:10)
at Module.load (module.js:356:32)
at Function.Module._load (module.js:312:12)
at Module.require (module.js:362:17)
at require (module.js:378:17)
at global.Controller (/apps/Foobar/globals.js:2:9)
at Object.<anonymous> (/apps/Foobar/app.js:282:1)
at Module._compile (module.js:449:26)
at Object.Module._extensions..js (module.js:467:10)
at Module.load (module.js:356:32)
at Function.Module._load (module.js:312:12)
at Module.runMain (module.js:492:10)
at process.startup.processNextTick.process._tickCallback (node.js:245:9)
As you can see I'm having the darnedest time trying to fix this issue with S3, and I'm to the point of crying (metaphorically). I can't keep wasting time on this issue, but I can't seem to solve it. It's almost like Node itself is broken.
Can anyone provide any insight on what's going on? Any help with this is appreciated.
Why isn't knox working anymore?
EDIT
Here's more details.
Code that errors:
// S3
var endpoint = "https://s3.amazonaws.com/"+global.config.aws.s3.bucket+"/";
var knox = require('knox');
var s3 = knox.createClient(global.config.aws.s3);
var photosPrefix = 'photos/';
var model = module.exports;
model.emitter = new events.EventEmitter;
// ::Photos
model.createPhoto = function(info, cb){
if (!info.file || path.resolve(info.file) === path.resolve(global.__tempdir))
return cb(new Error('missing info.file'));
var db = info.db;
var photoId;
if (typeof info.public === 'undefined')
info.public = false;
// Move file to a specific location
var basename = path.basename(info.file);
var destination = photosPrefix+basename+'/original';
yarn
(function(){
// Upload photo to AWS
s3.putFile(
info.file,
destination,
{
'Content-Type': 'image/png'
},
this());
})
(function(err, res){
if (err) return this.error(new Error(err));
// Remove temporary file
fs.unlink(info.file, this());
})
(function(err){
if (err) return this.error(new Error(err));
// Retrieve photo stream from AWS
s3.getFile(destination, this());
})
(function(err, res){
if (err) return this.error(new Error(err));
// Get the dimensions of the photo using the stream (res)
gm(res).size(this());
})
(function(err, size){
if (err) return this.error(new Error(err));
// Insert record into photos table (include the dimensions, width and height)
db.query("INSERT photos (resource, width, height, public) VALUES (?, ?, ?, ?)", [basename, size.width, size.height, info.public], this());
})
(function(err, results){
if (err) return this.error(new Error(err));
photoId = results.insertId;
cb(null, photoId);
})
.error(function(err){
cb(err);
});
}
All photos no matter what the size or format cause the same error.
I found that the issue wasn't with AWS and knox, but rather with gm and the fact that GraphicsMagick wasn't installed on my system.
For reference for others, if you're experiencing similar errors, remember that gm doesn't report that GraphicsMagick or ImageMagick are absent when they are absent. I reported this error on the gm module here: https://github.com/aheckmann/gm/issues/273