PostgreSQL

PostgreSQL is a production-ready, open-source database. It's a great choice database for many web applications, and as a back-end engineer, it might be the single most important database to be familiar with.

How does PostgreSQL work?

Postgres, like most other database technologies, is itself a server. It listens for requests on a port (Postgres' default is :5432), and responds to those requests. To interact with Postgres, first you will install the server and start it. Then, you can connect to it using a client like psql or PGAdmin.

1. Install

Mac OS

I recommend using brew to install PostgreSQL on Mac OS.

brew install postgresql

Linux (or WSL)

I recommend using apt to install PostgreSQL on Linux (Ubuntu). Here are the docs from Microsoft. The basic steps are:

sudo apt update
sudo apt install postgresql postgresql-contrib

2. Ensure the installation worked

The psql command-line utility is the default client for Postgres. Use it to make sure you're on version 14+ of Postgres:

psql --version

3. Start the Postgres server in the background

Mac OS

brew services start postgresql

Linux (or WSL)

sudo service postgresql start

4. Connect to the server using a client

I'm going to recommend using the PGAdmin client. It's a GUI that makes it easy to interact with Postgres and provides a lot of useful features. If you want to use psql on the command line instead, you're welcome to do so.

Download PGAdmin here.
Open PGAdmin and create a new server connection. Here are the connection details you'll need:

Mac OS (with brew)

Host: localhost
Port: 5432
Username: Your Mac OS username
Password: leave this blank

Linux (or WSL)

If you're on Linux, you have one more step before you can connect with credentials. On your command line run:

sudo passwd postgres

Enter a new password and remember it. Then restart your shell session.

Host: localhost
Port: 5432
Username: postgres
Password: the password you created

5. Create a database

A single Postgres server can host multiple databases. In the dropdown menu on the left, open the Localhost tab, then right click on "databases" and select "create database".

Name it whatever you like, but you'll need to know the name.

6. Query the database

Right click on your database's name in the menu on the left, then select "query tool". You should see a new window open with a text editor. In the text editor, type the following query:

SELECT version();

And click the triangle icon (execute/refresh) to run it. If you see a version number, you're good to go!

PGAdmin is the "thunder client" of Postgres. It's just a GUI that allows you to run ad-hoc queries against your database.