Ecto and PostgreSQL

Ecto it the database wrapper for mainly Postgresql. If you come from Ruby on Rails it is used instead of ActiveRecord but it is not an ORM. Ecto is a library and domain-specific language to interact with your database. It has four main components that can be used together all by itself.

Ecto.Schema

use Ecto.Schema

schema "products" do
  field :description, :string
  field :name, :string

  timestamps()
end

Ecto.Changeset

import Ecto.Changeset

def changeset(product, attrs) do
  product
  |> cast(attrs, [:name, :description])
  |> validate_required([:name, :description])
end

Ecto.Repo

Ecto.Query

import Ecto.Query

def list_active_products do
  from(
    p in Product,
    where: p.active == true,
    order_by: p.name
    order_by: [desc: p.name, desc: p.inserted_at],
    limit: 10
  )
  |> Repo.all()
end