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: