# EctoVista - PostgreSQL views for Ecto
Useful methods to define and manage PostgreSQL views in Ecto.
Inspired by [scenic](https://github.com/scenic-views/scenic) library for ActiveRecord (RoR)
## Installation
If [available in Hex](https://hex.pm/docs/publish), the package can be installed
by adding `ecto_vista` to your list of dependencies in `mix.exs`:
```elixir
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
- [x] Support `Model.refresh` callback in Ecto.Schema for Materialized Views
- [x] 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](https://github.com/elixir-lang/ex_doc)
and published on [HexDocs](https://hexdocs.pm). Once published, the docs can
be found at [https://hexdocs.pm/ecto_vista](https://hexdocs.pm/ecto_vista).
## License
The source code is under the Apache 2 License.
