Connecting with psql

This guide explains how to connect to a Hydra database using the psql command-line tool. It walks through the necessary setup, connection process, and execution of a simple SQL query.

Variables

To connect to a Hydra database, you only need one environment variable — the connection URI.

A typical URI looks like this:

postgresql://<USER>:<PASSWORD>@<HOST>:<PORT>/<DATABASE>

You can find the details needed in the URI from the Elestio service overview details. Copy and replace the variables carefully in the URI example provided above.

Prerequisites

While following this tutorial, you will need to have psql already installed; if not head over to https://www.postgresql.org/download/ and download it first.

Connecting to Hydra

Open your terminal and run the following command to connect to your Hydra database using the full connection URI:

psql HYDRA_URI

If the connection is successful, you’ll see output similar to this. Here it will show you the database you tried to connect to, which in this case is Elestio:

psql (17.4, server 14.13 (Debian 14.13-1.pgdg120+1))
SSL connection (protocol: TLSv1.3, cipher: TLS_AES_256_GCM_SHA384, compression: off, ALPN: none)
Type "help" for help.

elestio=# 

To ensure you're connected correctly, run this command inside the psql prompt:

SELECT version();

You should receive output like the following:

version
---------------------------------------------------------------------------------------------------------------------
PostgreSQL 16.8 (Debian 16.8-1.pgdg120+1) on x86_64-pc-linux-gnu, compiled by gcc (Debian 12.2.0-14) 12.2.0, 64-bit
(1 row)