Openwhisk failing to call compose postgre sql

I have tried for more hours than I care to admit to get an openWhisk function to call a postgre sql datbase on Compose.io. Here is my code:

My latest incarnation is this:

function myAction(params) {
 return new Promise(function(resolve, reject) {
    console.log('Connecting to Compose database');
	// console.log('Params ---> ', params);
    var mysql = require('promise-mysql');
	var fs = require('fs');
	var pg = require('pg');
	var request = require('request')
	var Promise = require('promise/lib/es6-extensions');
	var connString = "postgres:xxxx";
	
	
	
	 pg.connect(connString, function(err, client, done) {
		 console.log("connectiong..", err, client, done);
		 
          if (err) {

            console.log('[connectToCompose] failed to fetch client from pool', err);
            reject(err);

          } else {
            params.client = client; params.done = done;
            console.log('[connectToCompose] obtained a Compose client');
            return(params);

          }
       
		})
		
	//	params.client.done();
	//	console.log("closing connectiong");
 })

}

exports.main = myAction;

I have a similar example where I connect to a different SQL database (not Compose) and use sql promise not postgre and it works. What am I doing wrong?

To work with OpenWhisk and any database offering, you need to use promisified JavaScript code; the event loop as it's used in ordinary nodejs isn't available. I have an example that uses pg-promise (taken more or less exactly from the project docs) and it works fine for me. Try something like this:

const promise = require('bluebird');

const initOptions = {
    promiseLib: promise // overriding the default (ES6 Promise);
};

const pgp = require('pg-promise')(options);
const conn_info = {...connection info...};

const db = pgp(conn_info);

module.exports.main = function main(args) {
    db.any('SELECT * FROM items')
        .then(data => {
            console.log('DATA:', data);
            // return whatever data you wanted
            resolve({message: 'success'});
        })
        .catch(error => {
            console.log('ERROR:', error);
        });
}

Not all of the dependencies here are available on OpenWhisk by default, so when you deploy the action, include both your *.js file and the whole of node_modules/ in a zip file, and upload that. It's definitely possible to use the Compose Postgres with OpenWhisk, if that helps to encourage you :)