@graphile-contrib/pg-many-to-many

@graphile-contrib/pg-many-to-many

This Graphile Engine plugin adds connection fields for many-to-many relations.

Example:

{
  allPeople {
    nodes {
      personName
      # 👇 many-to-many relation
      teamsByTeamMemberPersonIdAndTeamId {
        nodes {
          teamName
        }
      }
    }
  }
}

Installation

yarn add @graphile-contrib/pg-many-to-many

Requires postgraphile@^4.1.0-rc.2 or graphile-build-pg@^4.1.0-rc.2

Usage

Append this plugin and the additional fields will be added to your schema.

Usage - CLI

postgraphile --append-plugins @graphile-contrib/pg-order-by-related -c postgres:///my_db

Usage - Library

const express = require("express");
const { postgraphile } = require("postgraphile");
const PgManyToMany = require("@graphile-contrib/pg-many-to-many");

const app = express();

app.use(
  postgraphile(process.env.DATABASE_URL, "app_public", {
    appendPlugins: [PgManyToMany]
  })
);

app.listen(process.env.PORT || 3000);

Inflection

To avoid naming conflicts, this plugin uses a verbose naming convention (e.g. teamsByTeamMemberTeamId), similar to how related fields are named by default in PostGraphile v4.

You can override this by adding an inflector plugin. For example, the following plugin shortens the names to just the table name (producing e.g. teams):

const { makeAddInflectorsPlugin } = require("graphile-utils");

module.exports = makeAddInflectorsPlugin(
  // TODO
);

See the makeAddInflectorsPlugin documentation for more information.