I want to display and edit data from a existing PostgreSQL database in an Angular Web Application.
I am completely new to angular and stuff.
I downloaded pg and express already.
After a look on this page: https://developer.mozilla.org/en-US/docs/Learn/Server-side/Express_Nodejs/mongoose
I figured I will need jugglingdb to connect the database to angular: https://npm.taobao.org/package/jugglingdb or https://www.npmjs.com/package/connect-jugglingdb
-> more specific: Juggling-db with postgres: https://npm.taobao.org/package/jugglingdb-postgres
So I created a new file called postgres.js:
var Schema = require('jugglingdb').Schema;
var schema = new Schema('postgres', {
database: 'mydatabase',
username: 'myusername',
host: 'myhostname', //I don't use the local user
port: XXXX,
password: s.password,
ssl: false
});
var Model = schema.define('Model', {
realNumber: {type: Number, dataType: 'float'}
});
Then I tried it with the help of this answer: Restful Api express postgres database
so I created a File called "dbconnector.js
const express = require('express')
const bodyParser = require('body-parser')
const app = express()
const port = 1234
const db = require('./dbconnector')
// 'db' is exported from a file such as
// dbconnector.js.
app.get('/things', db.getThings)
//In dbconnector.js:
const Pool = require('pg').Pool
const pool = new Pool({
user: 'myuser',
host: 'myhost',
database: 'mydb',
password: 'mypassword',
port: 5432,
})
const getThings = (request, response) => {
pool.query('SELECT * FROM public.regulation',
(error, results) =>
{
if (error) {
throw error
}
response.status(200).json(results.rows)
})
}
module.exports = {
getThings
}
I have searched, read and tried a lot of tutorials.
But whatever I try - I just can't display the data from the database in the web applikation.
Any ideas how I shall proceed?
Do you know a complete guide (connecting the database and displaying the data?)
or do you have any links or tips?
Edit
Found this very useful Link to a download example: https://grokonez.com/frontend/angular/angular-6/angular-6-httpclient-postgresql-node-js-express-sequelize-crud-apis-post-get-put-delete
An Angular application typically runs in the browser, while your database lives on a server. In simple terms, you usually connect them up by building a backend to your application that exposes any required data to consumers via an API.
It looks like you are using NodeJS for your backend from the links that you posted, so you could look into creating a RESTful API using express.
Related
I am trying to migrate my google cloud app engine from Redis 3.x to 4.x. However, it appears that there have been some major changes in Redis 4.x. It appears that the client no longer autoconnect and there have been some chnages to the syntax. Here's what I have run
'use strict';
import {createClient} from 'redis';
// These are just values stored in environment variables.
const REDISHOST = process.env.REDIHOST;
const REDISPORT = process.env.REDIPORT;
const REDISAUTH = process.env.REDISAUTH;
const redisClient.createClient();
redisClient.host = REDISHOST;
redisClient.port = REDISPORT;
redisclient.auth = REDISAUTH;
redisClient.on('error', (err) => console.error(`##### REDIS ERR: ${err}.`));
await redisClient.connect();
I can tell that host, port, and auth is being set in redisClient, but when I connect, it tries to connect to localhost and fails. Any idea what I am missing here?
You need to pass the connection information in the call the createClient():
const redisClient = createClient({
socket: {
host: REDISHOST,
port: REDISPORT
},
password: REDISAUTH
})
There are lots of options for connecting. They are all detailed in the client configuration guide.
Here is my complete code for sql connection, all code I have got from stackoverflow issues.
Everywhere, I found the same code is being suggested, hence I also tried with the same.
I have some other application which uses same connection with NextJs and it works fine, however, If I try only with NodeJS code, it gives some socket hang up error (code:'ESOCKET' name:'ConnectionError').
Please make a note that TCP is already configured on remote server and its working fine with other applications.
Any help is appreciated, thank you.
const express = require('express');
const fs = require('fs');
const path = require('path');
const cheerio = require("cheerio");
const sql = require('mssql');
require('dotenv').config(); //to use the env variables
// config for your database
var config = {
user: process.env.DATABASE_USER,
password: process.env.DATABASE_PASSWORD,
server: process.env.DATABASE_HOST,
database: process.env.SOMEDB,
port: 14345, // process.env.DATABASE_PORT,
options: {
encrypt: true, // for azure
trustServerCertificate: false // change to true for local dev / self-signed certs
}
};
// make sure that any items are correctly URL encoded in the connection string
let appPool = new sql.ConnectionPool(config);
//I got error on below connect
sql.connect(config).then(function(pool) {
//It never reaches here, it directly goes to the catch block
app.locals.db = pool;
const server = app.listen(3000, function () {
const host = server.address().address
const port = server.address().port
console.log('Example app listening at http://%s:%s', host, port)
})
}).catch(function(err) {
console.error('Error creating connection pool', err)
});
I have the same issue.
Try to use mssql version 6.0.1, it works on my code, but for sure we need to figure out the problem, since we can't think to mantain forever an old version of a package.
I kept trying to find the solution with different different configuration changes.
Finally, I have made a proper config, which worked and now its connecting properly as well as returning the data from the table.
require('dotenv').config(); //to access the process.env params
const sql = require("mssql"); //mssql object
var dbConfig = {
user: "ajay",
password: "abcd123",
server: "your_remote_sql_server_path",
port: 1433,
database: "your_database_name",
options: {
database: 'your_database_name',
trustServerCertificate: true
}
};
try {
//connection config will be used here to connect to the local/remote db
sql.connect(dbConfig)
.then(async function () {
// Function to retrieve the data from table
const result = await sql.query`select top 1 * from table_name`
console.dir(result)
}).catch(function (error) {
console.dir(error);
});
} catch (error) {
console.dir(error);
}
I am not sure what was the exact issue, but as per the previous config and this one, it seems like adding database name to the options has solved the issue.
Please make sure to save all the sensitive data to the .env file. (which you can access as PROCESS.env.parametername)
For me in driver mssql#9.1.1 making encrypt=false worked
const config = {
user: process.env.DATABASE_USER,
password: process.env.DATABASE_PASSWORD,
server: process.env.DATABASE_HOST,
database: process.env.SOMEDB,
port: 14345, // process.env.DATABASE_PORT,
options: {
encrypt: false
}
};
I have Node.js code to connect to a MySQL database:
var mysql = require('mysql')
var express = require('express')
var app = express()
var connection = mysql.createPool({
connectionLimit: 50,
host : 'ip',
user : 'username',
password : 'pass',
database : 'mydb'
});
app.get('/', function(req, resp) {
connection.getConnection(function(error, tempCont) {
if(!!error) {
tempCont.release();
console.log('Error');
} else {
console.log('Connected!');
tempCont.query("select * from table", function(error, rows, fields) {
tempCont.release();
if(!!error) {
console.log('Error in the query');
} else {
resp.json(rows);
}
});
}
})
})
console.log("listening requests...")
app.listen(1337);
How do I secure an IP address, username and password used for connecting to a database so that is not visible in the code or configuration file?
Install the dotenv module by: npm install --save dotenv
Create a .env file at the root folder and write down the code:
DB_CONLIMIT=50
DB_HOST=ip
DB_USER=username
DB_PASSWORD=pass
DB_DATABASE=mydb
In your JavaScript file:
var mysql = require('mysql');
var express = require('express');
var app = express();
const dotenv = require('dotenv').config();
var connection = mysql.createPool({
connectionLimit : process.env.DB_CONLIMIT,
host : process.env.DB_HOST,
user : process.env.DB_USER ,
password : process.env.DB_PASSWORD ,
database : process.env.DB_DATABASE
});
You should be configuring your systems so that your service runs as its own user with its own protected files. This offers some protection so that even if another service is compromised, the intruding user's access is isolated from other components of your system. Don't run things as root.
As for how secrets are stored and accessed, that's up to you. You can have a configuration file if you want. Another option is to use environment variables. Ultimately; however, your secrets are going to have to be stored in plaintext somewhere for your system to read and use.
Another method worth mentioning is you could possibly separate your secrets from your applications by having a dedicated secrets service. All your applications would have to know about this service and from there they could request the secrets they need for their regular operation. This has the obvious caveat of all your applications depend on the secrets service on start up - if that goes down your applications won't be able to start or restart.
I am pretty new to heroku and node. While I was trying to connect to heroku db, the following error shows up.
Error: connect ECONNREFUSED 127.0.0.1:5432
I am using connection pooling:
var pg = require('pg');
var heroconfig =process.env.DATABASE_URL || "postgres://jykyslkwkdsvhz:3ba43ff7db0c8dv9a914bac02f55ce944d8ccec31b67f858df3a858faa386c8e#ec2-54-243-214-198.compute-1.amazonaws.com:5432/dfiijlh3fbe3g9";
//var pool1 = new Pool(heroconfig);
var pool1 = new Pool(heroconfig);
app.get('/db', function(req, res){
pool1.query('SELECT * FROM test_table;',function(err, result){
if(err){
res.status(500).send(err.toString());
} else{
res.send(JSON.stringify(result.rows));
}
});
});
I tried to look at similar questions form other users but could not find solution involving pooling.
Please help.
I figured it out partially,
Storing the configuration data as object as below makes it works
var heroconfig = {
user: 'username',
database: 'database name',
password: 'some pass word',
host: 'host name',
port: 5432,
max: 10,
idleTimeoutMillis: 30000,
};
However while using the line of code mentioned in my original question, where database url is stored into the variable, it is not working:
var heroconfig =process.env.DATABASE_URL || "postgres://jykyslkwkdsvhz:3ba43ff7db0c8dv9a914bac02f55ce944d8ccec31b67f858df3a858faa386c8e#ec2-54-243-214-198.compute-1.amazonaws.com:5432/dfiijlh3fbe3g9";
I am planning to store my credentials in a different file and require it in my server file which seems to be a better approach.
I know this is late, but according to the docs in order to use a connection string, you must do this:
const { Pool, Client } = require('pg')
const connectionString = 'postgresql://dbuser:secretpassword#database.server.com:3211/mydb'
const pool = new Pool({
connectionString: connectionString,
})
See here: https://node-postgres.com/features/connecting#connection-uri
I have had such an error. After a lot of hours of research, I found out that my server deployed to Heroku was trying to access my PC PostgreSQL database. But it should have connected to the added-on PostgreSQL database in Heroku. I mean my server wasn't connecting to the database link in production mode, it was connecting to the database in development mode. I fixed it in my code like this.
db.js contents:
// focus on const environment
const environment = process.env.NODE_ENV || "development";
const knex = require("knex");
const knexfile = require("./knexfile");
const db = knex(knexfile[environment]);
module.exports = db;
Iam trying to implement role based authentication with sails js and use node_acl middleware. Has anybody tried it before? What i see from acl documentation is
//Using the mongodb backend
acl = new acl(new acl.mongodbBackend(dbInstance, prefix));
How do I get the dbInstance object from SailsJs
I was just trying the same thing (not sure about the merits in that), and I managed to connect using the MongoDB Driver.
You have to
npm install mongodb --save
and then, assuming you have in your config/connections.js the following adapter information:
MyMongo: {
adapter: 'sails-mongo',
host: 'localhost', // defaults to `localhost` if omitted
port: 27017, // defaults to 27017 if omitted
user: '', // or omit if not relevant
password: '', // or omit if not relevant
database: 'someDB' // or omit if not relevant
},
You can now do the following:
var node_acl = require('acl');
var MongoClient = require('mongodb').MongoClient;
var dbInstance = "mongodb://"+sails.config.connections.MyMongo.host+":"+
sails.config.connections.MyMongo.port+"/"+sails.config.connections.MyMongo.database;
MongoClient.connect(dbInstance, function(error, db) {
//check for errors...
var mongoBackend = new node_acl.mongodbBackend(db, 'acl_');
var acl = new node_acl( mongoBackend );
acl.allow('role', 'model', 'action'); // Now you can do this...
}
I hope this helps. Notice I added the acl_ prefix so all the collections generated by ACL are discernible from other collections used by your models with sails.