---
title: PostgreSQL
---

# Setup your application with PostgreSQL

Follow the instructions in the installation guide below that corresponds to your operating system:

1. macOS
   - [Postgres.app](https://postgresapp.com/): PostgreSQL installation as a Mac app
   - [Homebrew](https://brew.sh/): if you use Homebrew you can easily install PostgreSQL with `brew install postgresql`
1. Linux (Ubuntu)
   - [Ubuntu `14.04`](https://www.digitalocean.com/community/tutorials/how-to-install-and-use-postgresql-on-ubuntu-14-04)
   - [Ubuntu `16.04 and higher`](https://www.digitalocean.com/community/tutorials/how-to-install-and-use-postgresql-on-ubuntu-16-04)
1. [Windows](https://www.postgresql.org/download/windows/)

_You can find all installation options for a variety of operating systems [on the official PostgreSQL download page](https://www.postgresql.org/download/)_.

## Configuration

By default the application is configured to connect to a local database named `PracticalDeveloper_development`. If you need to specify a username and a password you can go about it by using the environment variable `DATABASE_URL` with a connection string.

The [official Rails guides](https://guides.rubyonrails.org/configuring.html#connection-preference) go into depth on how Rails merges the existing `database.yml` with the connection string.

### Setup `DATABASE_URL` in application.yml

1. Open your `config/application.yml`

1. Add the following:

```yml
DATABASE_URL: postgresql://USERNAME:PASSWORD@localhost
```

1. Replace `USERNAME` with your database username, `PASSWORD` with your database password.

You can find more details on connection strings in [PostgreSQL's own documentation](https://www.postgresql.org/docs/10/static/libpq-connect.html#LIBPQ-CONNSTRING).

NOTE: due to how Rails merges `database.yml` and `DATABASE_URL` it's recommended not to add the database name in the connection string. This will default to your development database name also during tests, which will effectively empty the development DB each time tests are run.

## Troubleshooting tests

- While running test cases, if you get an error message `postgresql connection timeout`, please re-run the tests by increasing the statement timeout, for example:

```shell
STATEMENT_TIMEOUT=10000 bundle exec rspec
```
