pg_graphql: GraphQL for Postgres

pg_graphql is Postgres extension for interacting with the database using GraphQL instead of SQL.

The extension reflects a GraphQL schema from the existing SQL schema and exposes it through a SQL function, graphql.resolve(...). This enables any programming language that can connect to Postgres to query the database via GraphQL with no additional servers, processes, or libraries.

The pg_graphql resolve method is designed to interop with PostgREST, the tool that underpins the Supabase API, such that the graphql.resolve function can be called via RPC to safely and performantly expose the GraphQL API over HTTP/S.

For more information about how the SQL schema is reflected into a GraphQL schema, see the pg_graphql API docs.

Enable the extension

-- Enable the "pg_graphql" extension
create extension pg_graphql;

-- Disable the "pg_graphql" extension
drop extension if exists pg_graphql;

Usage

Given a table

create table "Blog"(
  id serial primary key,
  name text not null,
  description text
);

insert into "Blog"(name)
values ('My Blog');

The reflected GraphQL schema can be queried immediately as

select
  graphql.resolve($$
    {
      blogCollection(first: 1) {
        edges {
          node {
            id,
            name
          }
        }
      }
    }
  $$);

returning the JSON

{
  "data": {
    "blogCollection": {
      "edges": [
        {
          "node": {
            "id": 1,
            "name": "My Blog"
          }
        }
      ]
    }
  }
}

Note that pg_graphql supports schema introspection, so you can connect any GraphQL IDE or schema inspection tool to see the full set of fields and arguments available in the API. Starting from pg_graphql 1.6.0, introspection is disabled by default and must be enabled per schema:

comment on schema public is e'@graphql({"introspection": true})';

See the upgrade notes for details.

API

• graphql.resolve: A SQL function for executing GraphQL queries.

Resources

• Official pg_graphql documentation