I created a user in postgresql with this mand:

createuser --interactive

But it didn't ask for a new password, so I figured that the password is set to the sudo password of my puter. However, when I tried to connect to my database, using this code:

async function connect() {
    let connection_string = "postgres://[username]:[password]@localhost:5432/[database]"
    let client = new pg.Client(connection_string)
    await client.connect()

    let query = await client.query("select * from Messages;")
    query.rows.forEach(row => {
        console.log(row)
    })
    await client.end()
}

I received this error:

(node:7106) UnhandledPromiseRejectionWarning: error: password authentication failed for user "[username]"

How can I fix it?

I created a user in postgresql with this mand:

createuser --interactive

But it didn't ask for a new password, so I figured that the password is set to the sudo password of my puter. However, when I tried to connect to my database, using this code:

async function connect() {
    let connection_string = "postgres://[username]:[password]@localhost:5432/[database]"
    let client = new pg.Client(connection_string)
    await client.connect()

    let query = await client.query("select * from Messages;")
    query.rows.forEach(row => {
        console.log(row)
    })
    await client.end()
}

I received this error:

(node:7106) UnhandledPromiseRejectionWarning: error: password authentication failed for user "[username]"

How can I fix it?

• javascript
• node.js
• postgresql

• Just an FYI for anyone who gets here, if the parameter passed to new pg.Client() (ie connection_string in the above variable) is a bad URL, then you will get the same error regardless. For example new pg.Client(undefined) will also give the error error: password authentication failed for user <username>. Seems like it would be a good idea to give a more useful error message as this was pretty misleading for me. – JimmyTheCode Commented Oct 22, 2021 at 15:03
• If you're using node.js dotenv and pg make sure you have require('dotenv').config(); in your index.js. This fixed this error once I added it. – WHOATEMYNOODLES Commented Jan 22, 2022 at 9:05

7 Answers 7

Modifying access methods on the pg_hba.conf to trust, did it for me.

$ sudo nano /etc/postgresql/13/main/pg_hba.conf 

# "local" is for Unix domain socket connections only
local   all             all                                     trust
# IPv4 local connections:
host    all             all             127.0.0.1/32            trust
# IPv6 local connections:
host    all             all             ::1/128                 trust

reload the service, and try to connect again.

const DB_URI = "postgresql:///<database_here>";
let db = new Client({ connectionString: DB_URI });
db.connect();

This worked for me:

login to a priviledge user in psql

e.g. sudo -u postgres psql

create a new user:

CREATE USER new_user WITH PASSWORD 'password123';

change ownership of database:

ALTER DATABASE dbname OWNER TO new_owner;

change ownership of table:

ALTER TABLE public.table_name OWNER TO new_owner;

I dropped the user,

drop owned by [username];
drop user [username];

and re-created the user, this time instead with this mand:

createuser -P -s -e [username]

Now, it asks for a new password to be given to this user. And then the same code works fine.

    async function connect() {
        let connection_string = "postgres://[username]:[password]@localhost:5432/[database]"
        let client = null;
        try {
         new pg.Client(connection_string)
         } catch (e) {
          console.log (e);
return;
         }
try {
        await client.connect()
} catch (e) {
return;
}

try {
        let query = await client.query("select * from Messages;")
} catch(e) {
return ;
}
        query.rows.forEach(row => {
            console.log(row)
        })
        await client.end()
    }

You can handle the error by using try catch block. Now for why the error is ing, whatever username/password you are providing its wrong as its failing to connect with this details

I don't aware about Postgres DB, But I suggest one thing you need to do when working with NodeJS. NodeJS provides a unhandledRejection hook to handle every promise rejection globally. You can use it by adding such peace of code in your main file (server.js or app.js).

process.on('unhandledRejection', (reason, promise) => {
  // call a function which will send a mail of this rejection
});

You can get a better understanding by monitoring reason & promise. I hope it helps. Happy Coding :)

Please try with the below simple code for connecting with the PostgreSQL Database. Create a new user with credentials like username: education and password: password007 .

 var express = require('express'),
    pg = require('pg'),
    app = express();

//DB Connect String
var connect = "postgres://education:password007@localhost/recipebookdb";


app.get('/', function(req, res) {
    //Pg Connect
    // var pool = new pg.Pool()
    // console.log(req.params.user_id);
    pg.connect(connect, function(err, client, done) {
        if(err) {
            return console.error('error facing client from pool', err);
        }
        client.query('SELECT * FROM recipes', function (err, result) {
            if(err) {
                return console.error('error runnign query', err);
            }
            res.render('index', {recipes: result.rows});
            done();
        });
    });
});

You need to handle the error by using try catch also you need to log the reason for the unhandledRejection. here is an example as per your scenario

async function connect() {
    try {
        let connection_string = "postgres://[username]:[password]@localhost:5432/[database]"
        let client = new pg.Client(connection_string)
        await client.connect()
    } catch (err) {
        throw err;
    }
    try {
        let query = await client.query("select * from Messages;");

        query.rows.forEach(row => {
            console.log(row)
        })

        await client.end()
    } catch (err) {
        throw err;
    }
}

process.on('unhandledRejection', (reason, promise) => {
    console.log('Unhandled Rejection at:', reason.stack || reason)
  });