A First Look at PostGraphile with Railway
PostGraphile builds a GraphQL API from a PostgreSQL schema that automatically detects information such as tables, columns, indexes, and relationships
All of this project's code can be found in the First Look monorepo on my GitHub.
Introduction
PostGraphile builds a GraphQL API from a PostgreSQL schema that automatically detects tables, columns, indexes, relationships, views, types, functions, and comments. It combines PostgreSQL's role-based grant system and row-level security policies with Graphile Engine's GraphQL look-ahead and plugin expansion technologies.
Provision a PostgreSQL database with Railway
There are two ways to setup a PostgreSQL database with Railway, through the dashboard or through the CLI.
Railway Dashboard
Click dev.new and choose "Provision PostgreSQL" After the database is setup click "PostgreSQL" on the left and then choose "Connect". Copy and paste the PostgreSQL client command.
Railway CLI
First you need to install the Railway CLI.
Check Railway CLI version
railway version
railway version 0.2.40
Login with railway login
If you do not have a Railway account you will be prompted to create one.
railway login
Initialize project with railway init
Run the following command, select “Empty Project,” and give your project a name.
railway init
Provision PostgreSQL with railway add
Run the following command and select PostgreSQL to add a plugin to your Railway project.
railway add
Connect to database
railway connect postgresql
psql (13.3, server 13.2)
SSL connection (protocol: TLSv1.3, cipher: TLS_AES_256_GCM_SHA384, bits: 256, compression: off)
Type "help" for help.
railway=#
Seed database
Run the following SQL commands to create a test table with seed data.
CREATE TABLE Post (title text, body text);
INSERT INTO Post VALUES ('This is a blog post', 'Wooooooo');
INSERT INTO Post VALUES ('Another blog post', 'Even better than the other!');
List tables in database
\d
List of relations
Schema | Name | Type | Owner
--------+------+-------+----------
public | post | table | postgres
(1 row)
Describe table
\d post
Table "public.post"
Column | Type | Collation | Nullable | Default
--------+------+-----------+----------+---------
title | text | | |
body | text | | |
Quit psql
\q
Copy database connection string to clipboard
echo `railway variables get DATABASE_URL` | pbcopy
Introspect Database with PostGraphile
It is easy to install PostGraphile with npm, although the PostGraphile documentation does not recommend installing PostGraphile globally if you want to use plugins.
npm install -g postgraphile
If you do not globally install you will need to add npx the beginning of all postgraphile commands in this tutorial.
Introspect Railway Database
railway run postgraphile --watch --enhance-graphiql --dynamic-json --port 5001
Open localhost:5001/graphiql and send the following query.
Test the endpoint
curl \
--request POST \
--url "http://localhost:5001/graphql" \
--header "Content-Type: application/json" \
--data '{"query":"{ query { allPosts { totalCount nodes { body title } } } }"}'
{
"data":{
"query":{
"allPosts":{
"totalCount":2,
"nodes":[
{
"body":"Wooooooo",
"title":"This is a blog post"
},
{
"body":"Even better than the other!",
"title":"Another blog post"
}
]
}
}
}
}
Connect to endpoint with ngrok
ngrok provides an instant, secure URL to your localhost server through any NAT or firewall where you can introspect all HTTP traffic running over your tunnels.
./ngrok http 5001
Session Status online
Account Anthony Campolo (Plan: Free)
Version 2.3.40
Region United States (us)
Web Interface http://127.0.0.1:4040
Forwarding http://363ef1ef5cf3.ngrok.io -> http://localhost:5001
Forwarding https://363ef1ef5cf3.ngrok.io -> http://localhost:5001
Connections ttl opn rt1 rt5 p50 p90
2 0 0.00 0.00 5.11 5.21
Send the same query with your API tool of choice.
