PgRanges

PostgreSQL range types for Ecto.

PgRanges provides a simple wrapper around Postgrex.Range so that you can create schemas with range type fields and use the native range type in migrations.

defmodule MyApp.Employee do
  use Ecto.Schema
  alias PgRanges.DateRange

  schema "employees" do
    field :name, :string
    field :employed_dates, DateRange
  end
end

defmodule MyApp.Repo.Migrations.CreateEmployees do
  use Ecto.Migration

  def change do
    create table(:employees) do
      add :name, :string
      add :employed_dates, :daterange
    end
  end
end

When used in composing queries, you must cast to the PgRange type.

import Ecto.Query
alias PgRanges.DateRange
alias MyApp.Repo

range = DateRange.new(~D[2018-11-01], ~D[2019-01-01])

Repo.all(
  from e in Employee,
  where: fragment("? @> ?", e.employed_dates, type(^range, DateRange))
)

Installation

The package can be installed by adding pg_ranges to your list of dependencies in mix.exs:

def deps do
  [
    {:pg_ranges, "~> 1.1.1"}
  ]
end

Dev Setup

While trying to not be prescriptive about how to work on this package, I recommend using VSCode with the Dev Containers and ElixirLS extensions. The .gitignore file ignores .devcontainer/ and .vscode/ directories, so feel free to use whatever you deem necessary.

Basic Dev Container Setup

.devcontainer/Dockerfile:

FROM elixir:1.16
WORKDIR /workspace

.devcontainer/docker-compose.yaml:

version: '3'
services:
  db:
    image: postgres
    restart: unless-stopped
    environment:
    - POSTGRES_USER=pgranges
    - POSTGRES_PASSWORD=pgranges
  code:
    build:
      context: ..
      dockerfile: .devcontainer/Dockerfile
    command: sleep infinity
    volumes:
    - ..:/workspace:cached
    depends_on:
    - db

.devcontainer/devcontainer.json:

{
  "name": "pg_range",
  "dockerComposeFile": "docker-compose.yaml",
  "service": "code",
  "workspaceFolder": "/workspace"
}

Running the Tests

Local Only (Not in a Dev Container)

First, you'll need a locally running Postgres server. The easiest way to do this is using Docker:

$ docker pull postgres
$ docker run -p 5432:5432 -e POSTGRES_USER=pgranges -e POSTGRES_PASSWORD=pgranges postgres

To run the tests:

$ mix test