Connection getting skipped when connecting to Postgress DB - node.js

Question

I'm writing a lambda function to connect to a postgress DB that I have on an EC2 instance. I've been utilizing the 'pg' library for connecting as found in their documentation, however, my function keeps skipping over the establish connection piece of my method and just continuing and exiting without accomplishing anything.
const client = new Client({
user: 'user',
host: 'xxxx.xxx.xxxx',
database: 'dbname',
password: 'password',
port: 5432,
})
client.connect(err => {
if (err) {
console.error('connection error', err.stack)
} else {
console.log('connected')
}
})
client.query('select count(*) from "Product"', (error, results) => {
if (error) {
console.log("Error when trying to query");
throw error
}
console.log(results.rows)
})
I'm going exactly by the methods that the 'pg' documentation says (https://node-postgres.com/features/connecting), but can't figure out what is going wrong here. I'm using serverless with nodejs12.x for this function.

Answer 1

You are not waiting for the connection to be established before querying. Try this:
const client = new Client({
user: 'user',
host: 'xxxx.xxx.xxxx',
database: 'dbname',
password: 'password',
port: 5432,
})
return client.connect(err => {
if (err) {
console.error('connection error', err.stack)
} else {
console.log('connected')
return client.query('select count(*) from "Product"', (error, results) => {
if (error) {
console.log("Error when trying to query");
throw error
}
console.log(results.rows)
})
}
})
Although, if your can, create a promise chain as it is probably easier to manage like so:
const client = new Client({
user: 'user',
host: 'xxxx.xxx.xxxx',
database: 'dbname',
password: 'password',
port: 5432,
})
return client.connect().then(()=>{
return client.query('select count(*) from "Product"')
}).then((results)=>{
console.log(results.rows)
}).catch((err)=>{
console.error('error', err.stack? err.stack : err)
})
I say use a promise chain if you can because Im not sure what the pg library returns on connect and query..
Hope this helps!