ArangoDB.Ecto

Ecto 2.x adapter for ArangoDB.

It converts Ecto.Query structs to AQL. At the moment the from, where, order_by, limit offset and select clauses are supported.

For example, this Ecto query:

from u in "users",
  where: like(u.name, "A%") and u.age > 18,
  select: [u.name, u.age],
  order_by: [desc: u.name],
  limit: 10

results in the following AQL query:

FOR u0 IN `users`
  FILTER ((u0.`name` LIKE 'A%') && (u0.`age` > 18))
  SORT u0.`name` DESC
  LIMIT 10
  RETURN { `name`: u0.`name`, `age`: u0.`age` }

Usage

In the repository configuration, you need to specify the :adapter:

config :my_app, MyApp.Repo,
  adapter: ArangoDB.Ecto,
  database: "my_app"
  ...

The following options can be defined to configure the connection to ArangoDB. Unless specified otherwise, the show default values are used.

host: "localhost",
port: 8529,
scheme: "http",
database: "_system",
arrango_version: 30_000,
headers: %{"Accept": "*/*"},
use_auth: :basic,
username: nil,
password: nil,

When defining your schema, you should use ArangoDB.Ecto.Schema instead of Ecto.Schema. This implicitly defines the primary key to be the autogenerated id, mapping it to Arango’s _key field.

If you pass in the option arango_key: true, this translation will not be done, and your primary key will be _key. In this case, you will have to manually specify the foreign_key when using associations. E.g. foreign_key: author__key

defmodule User do
  use ArangoDB.Ecto.Schema

  schema "users" do
    field :name, :string
    field :age, :integer
    has_many :posts, Post
    timestamps()
  end
end

defmodule Post do
  use ArangoDB.Ecto.Schema

  schema "posts" do
    field :title, :string
    field :text, :binary
    belongs_to :author, User
    timestamps()
  end
end

Installation

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

def deps do
  [{:arangodb_ecto, "~> 0.1.0"}]
end

Features not yet implemented

• subqueries
• joins
• on conflict
• upserts

Testing

Before running the tests, configure access to your Arango database by setting these environment variables:

• ARANGO_SRV
• ARANGO_USR
• ARANGO_PWD