Postgres databases linked to separate Heroku environments - postgresql

Question

Using this article: Heroku dev environments
I successfully made two separate Heroku apps, one test, and one prod. This each have their own remotes on my local development box. But now I don't know how to separate the postgres tables of my now distinct development and prod applications.
This is the command I use to create a postgres table with my Heroku app:
heroku addons:add heroku-postgresql
But then I lost access to my original postgres DB. I would like this setup so I don't inadvertently hose my prod DB from my development branch.
TL;DR: How do i keep distinct postgres databases with a single Heroku application that has multiple environments?
EDIT #1: I found that I can call:
heroku addons:add heroku-postgresql:dev
multiple times to create several dev databases. What is the best practice for pointing my dev vs. prod apps to each database without having to hard code my database links like this:
//this function connects to the Heroku postgres db
function pg_connection_string(){
return "dbname=dcs1k5588jbfad host=ec2-54-243-224-162.compute-1.amazonaws.com port=5432 user=###user_name### password=######### sslmode=require";
}
Is there a Heroku-fung-shui of swapping database pointers?

Answer 1

You can set the environment variable or heroku config variable DATABASE_URL to anything you wish. This is what Heroku applications expect to be the default database for that application.
If you're using a production Database you can Fork from your production app to a test app to get a copy of the data as well: https://devcenter.heroku.com/articles/heroku-postgres-fork