XUtils

ecto

A database wrapper and language integrated query for Elixir.

Elixir
https://github.com/elixir-ecto/ecto

About

Ecto is a toolkit for data mapping and language integrated query for Elixir. Here is an example:

# In your config/config.exs file
config :my_app, ecto_repos: [Sample.Repo]

config :my_app, Sample.Repo,
  database: "ecto_simple",
  username: "postgres",
  password: "postgres",
  hostname: "localhost",
  port: "5432"

# In your application code
defmodule Sample.Repo do
  use Ecto.Repo,
    otp_app: :my_app,
    adapter: Ecto.Adapters.Postgres
end

defmodule Sample.Weather do
  use Ecto.Schema

  schema "weather" do
    field :city     # Defaults to type :string
    field :temp_lo, :integer
    field :temp_hi, :integer
    field :prcp,    :float, default: 0.0
  end
end

defmodule Sample.App do
  import Ecto.Query
  alias Sample.{Weather, Repo}

  def keyword_query do
    query =
      from w in Weather,
           where: w.prcp > 0 or is_nil(w.prcp),
           select: w

    Repo.all(query)
  end

  def pipe_query do
    Weather
    |> where(city: "Kraków")
    |> order_by(:temp_lo)
    |> limit(10)
    |> Repo.all
  end
end

Ecto is commonly used to interact with databases, such as PostgreSQL and MySQL via Ecto.Adapters.SQL (source code). Ecto is also commonly used to map data from any source into Elixir structs, whether they are backed by a database or not.

See the getting started guide and the online documentation for more information. Other resources available are:

  • Programming Ecto, by Darin Wilson and Eric Meadows-Jönsson, which guides you from fundamentals up to advanced concepts

  • The Little Ecto Cookbook, a free ebook by Dashbit, which is a curation of the existing Ecto guides with some extra contents

Running tests

Clone the repo and fetch its dependencies:

$ git clone https://github.com/elixir-ecto/ecto.git
$ cd ecto
$ mix deps.get
$ mix test

Note that mix test does not run the tests in the integration_test folder. To run integration tests, you can clone ecto_sql in a sibling directory and then run its integration tests with the ECTO_PATH environment variable pointing to your Ecto checkout:

$ cd ..
$ git clone https://github.com/elixir-ecto/ecto_sql.git
$ cd ecto_sql
$ mix deps.get
$ ECTO_PATH=../ecto mix test.all

Running containerized tests

It is also possible to run the integration tests under a containerized environment using earthly:

$ earthly -P +all

You can also use this to interactively debug any failing integration tests using:

$ earthly -P -i --build-arg ELIXIR_BASE=1.8.2-erlang-21.3.8.21-alpine-3.13.1 +integration-test

Then once you enter the containerized shell, you can inspect the underlying databases with the respective commands:

PGPASSWORD=postgres psql -h 127.0.0.1 -U postgres -d postgres ecto_test
MYSQL_PASSWORD=root mysql -h 127.0.0.1 -uroot -proot ecto_test
sqlcmd -U sa -P 'some!Password'

“Ecto” and the Ecto logo are Copyright © 2020 Dashbit.

The Ecto logo was designed by Dane Wesolko.

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