EctoVista - PostgreSQL views for Ecto

Useful methods to define and manage PostgreSQL views in Ecto.

Inspired by scenic library for ActiveRecord (RoR)

Installation

If available in Hex, the package can be installed by adding ecto_vista to your list of dependencies in mix.exs:

def deps do
  [
    {:ecto_vista, "~> 0.2.0"}
  ]
end

Basic Usage

1. Add ecto_vista to your list of dependencies in mix.exs and run:

mix deps.get

2. Generate your migration for the view, put the view definition like the one below inside change or up method:

execute("""
  CREATE MATERIALIZED VIEW catalog_v1 AS
    SELECT c.*, count(p.id) AS product_count
    FROM categories c
    LEFT JOIN products p ON c.id = p.category_id
    GROUP BY c.id
  ;
""")

3. Use EctoVista module in your Ecto schema:

def App.Catalog do
  use Ecto.Schema
  use EctoVista,
    repo: App.Repo
    table_name: "catalog"

  schema @table_name do
    field(:name, :string)
    field(:product_count, :integer)
  end
end

The @table_name will be defined in macro as {table_name}_v{version} (version is 1 by default) This naming convention facilitates 0-downtime view updates and will be handled automagically in future versions.

If you need to update the view, generate a new migration and then just update the version number in the schema definition:

def App.Catalog do
  use Ecto.Schema
  use EctoVista,
    repo: App.Repo
    table_name: "catalog"
    version: 2

  ...
end

4. Don't forget to refresh your materialized view to see data:

iex> Catalog.refresh
:ok

Roadmap

M1

• Support Model.refresh callback in Ecto.Schema for Materialized Views
• Implement automatic view versioning for a model
• Support create view callback in Ecto.Migration

M2

• Support all options to refresh and create views
• Implement automatic view versioning for migration

Docs

Documentation can be generated with ExDoc and published on HexDocs. Once published, the docs can be found at https://hexdocs.pm/ecto_vista.

License

The source code is under the Apache 2 License.