til/postgres/fetch-data-from-an-endpoint-in-sql.md

Fetch Data From An Endpoint In SQL

The pgsql-http extension provides a variety of functions for allowing PostgreSQL to act as an HTTP client. This is a bit unorthodox and may not be a good idea in production systems. That said, it is cool that it is possible. Let's look at an example of it.

First, I've installed the extension on the Docker container running my local Postgres server.

$ docker exec -it still-postgres-1 bash

$ apt-get update

$ apt-get install postgres-16-http # I'm running Postgres v16

$ exit

Then I'll connect to a psql session in that container for the postgres database.

$ docker exec still-postgres-1 psql -U postgres -d postgres

Then I enable the extension.

> create extension if not exists http;
CREATE EXTENSION

Now I can point a PostgreSQL statement at a live endpoint like https://httpbun.com/ip which will respond with a chunk of JSON including the IP address for that project's server. I do this using http_get which makes a GET request to the given endpoint. The body is included in the result set.

> select content from http_get('http://httpbun.com/ip');
           content
-----------------------------
 {                          +
   "origin": "73.75.236.101"+
 }                          +

(1 row)