Version: 0.14.x

GraphQL Migrations

Graphback uses graphql-migrations to automatically create and update tables from a GraphQL schema. The library compares your database schema to your GraphQL schema and executes the required changes to keep the database structure synchronised with the GraphQL schema.

Compatibility

  • PostgreSQL (create and update database)
  • SQLite (create database only)

Installation

You can install graphql-migrations on your existing project using the following commmands:

With npm:

npm i graphql-serve

or with yarn:

yarn add graphql-serve

Usage

GraphQL Migrations operates on business models defined in your schema: These are GraphQL types decorated with a @model annotation. The package expose an API which you can programmatically set up in your source code and have it perform the migrations.

The package exposes a migrateDB method which creates and updates your tables and columns to match your GraphQL schema. All the database operations are wrapped in a single transaction, so your database will be fully rolled back to its initial state if an error occurs. The method takes three arguments as described in migrations options section.

import { migrateDB } from 'graphql-migrations';
const schemaText = ```
"""
@model
"""
type Note {
id: ID!
title: String!
}
```;
const dbConfig = {
// Knex.js based configuration
};
migrateDB(dbConfig, schemaText, {
// Additional options
}).then((ops) => {
console.log(ops);
});
...

Assuming the above code is ran against a PostgreSQL database, the following relations will be created:

\d
List of relations
Schema | Name | Type | Owner
--------+-------------+----------+------------
public | note | table | postgresql
public | note_id_seq | sequence | postgresql

And the note table:

\d note
Table "public.note"
Column | Type | Modifiers
--------+------------------------+---------------------------------------------------
title | character varying(255) | not null
id | integer | not null default nextval('note_id_seq'::regclass)
Indexes:
"note_pkey" PRIMARY KEY, btree (id)

Advanced usage

For more advanced usage, visit the below pages: