cat-bookmarker/deps/ecto/README.md at 48d07472c9f1c4cb6e142e213b3799c6834c1751

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Installation

Add :ecto to the list of dependencies in mix.exs:

def deps do
  [
    {:ecto, "~> 3.10"}
  ]
end

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

Usage

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
PostgreSQL	Ecto.Adapters.Postgres	ecto_sql + postgrex
MySQL	Ecto.Adapters.MyXQL	ecto_sql + myxql
MSSQL	Ecto.Adapters.Tds	ecto_sql + tds
SQLite3	Ecto.Adapters.SQLite3	ecto_sqlite3
ClickHouse	Ecto.Adapters.ClickHouse	ecto_ch
ETS	Etso	etso

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"}
  ]
end

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
v3.11	Bug fixes
v3.10	Security patches only
v3.9	Security patches only
v3.8	Security patches only
v3.7	Security patches only
v3.6 and earlier	Unsupported

With version 3.0, Ecto API has become stable. Our main focus is on providing bug fixes and incremental changes.

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
$ 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'

Logo

The Ecto logo was designed by Dane Wesolko.

License

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 https://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.

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