A toolkit for data mapping and language integrated query for Elixir




Build Status

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

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

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


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

Ecto is commonly used to interact with databases, such as Postgres and MySQL via Ecto.Adapters.SQL (source code). Ecto is also commonly used to map data from any source into Elixir structs, regardless if 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 Plataformatec, which is a curation of the existing Ecto guides with some extra contents


You need to add both Ecto and the database adapter as a dependency to your mix.exs file. The supported databases and their adapters are:

Database Ecto Adapter Dependencies Ecto 3.0 compatible?
PostgreSQL Ecto.Adapters.Postgres ecto_sql + postgrex Yes
MySQL Ecto.Adapters.MyXQL ecto_sql + myxql Yes
MSSQL MssqlEcto ecto_sql + mssql_ecto No
MSSQL Tds.Ecto ecto_sql + tds_ecto No
SQLite     Sqlite.Ecto2   ecto + sqlite_ecto2 No
Mnesia     EctoMnesia.Adapter   ecto + ecto_mnesia No

For example, if you want to use PostgreSQL, add to your mix.exs file:

defp deps do
    {:ecto_sql, "~> 3.0"},
    {:postgrex, ">= 0.0.0"}

Then run mix deps.get in your shell to fetch the dependencies. If you want to use another database, just choose the proper dependency from the table above.

Finally, in the repository definition, you will need to specify the adapter: respective to the chosen dependency. For PostgreSQL it is:

defmodule MyApp.Repo do
  use Ecto.Repo,
    otp_app: :my_app,
    adapter: Ecto.Adapters.Postgres,

Supported Versions

Branch Support
v3.1 Bug fixes
v3.0 Security patches only
v2.2 Security patches only
v2.1 Unsupported from 10/2018
v2.0 Unsupported from 08/2017
v1.1 Unsupported from 03/2018
v1.0 Unsupported from 05/2017

With the version 3.0, Ecto has become API stable. This means no more new features, although we will continue providing bug fixes and updates. For everyone running Ecto in production, rest assured that Ecto will continue to be a well maintained project with the same production quality and polish that our users are familiar with.

Important links

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
$ ECTO_PATH=../ecto mix test.all


"Ecto" and the Ecto logo are Copyright (c) 2020 Dashbit.

The Ecto logo was designed by Dane Wesolko.


Copyright (c) 2013 Plataformatec
Copyright (c) 2020 Dashbit

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.