Ecto.Rut v1.2.0 Ecto.Rut behaviour

Provides simple, sane and terse shortcuts for Ecto models.

Ecto.Rut is a wrapper around Ecto.Repo methods that usually require you to pass the module as the subject and sometimes even require you do extra work before hand, (as in the case of Repo.insert/3) to perform operations on your database. Ecto.Rut tries to reduce code repetition by following the “Convention over Configuration” ideology.

For example, once set up, it allows you to do this on a model called Post:

# Create a Post
Post.insert(title: "Introduction to Elixir", categories: ["Elixir", "Programming"])

# Get all Posts
Post.all

# Get a Post with its id
Post.get(3)

# Get a Post with another attribute
Post.get_by(published_date: "2016-02-24")

# Delete a Post
Post.delete(lame_post)

Installation

Once added to your mix dependencies, all you need to do is call use Ecto.Rut in your Ecto models:

defmodule YourApp.Post do
  use Ecto.Schema
  use Ecto.Rut

  # Schema, Changeset and other stuff...
end

Phoenix Projects

If you’re using Ecto with a Phoenix project, instead of calling use Ecto.Rut in all of your models, you can just call it once in the model/0 method of your web/web.ex file:

# web/web.ex

def model do
  quote do
    use Ecto.Schema
    use Ecto.Rut

    # Other stuff...
  end
end

Configuration

You can also pass options to Ecto.Rut when calling use on it. These values are inferred automatically by Ecto.Rut, but you can set them yourself in those special cases where it can’t. The two options are:

  • :model

    You set this when your Ecto Model is different from the module where you are calling use

  • :repo

    You set this when your app’s Ecto.Repo module is set differently.

defmodule YourApp.OtherNamespace.Post do
  use Ecto.Schema
  use Ecto.Rut,  model: YourApp.Post,  repo: YourApp.CustomEcto.Repo

  # Other Stuff
end

Export Changeset

Methods like insert/1 or update/2 depend on your model exporting a public function called changeset(struct, params) with all your desired validations and constraints applied to the casted struct.

Ecto.Rut uses this function to convert maps, keyword lists and other types into Ecto.Changeset, before updating or inserting them into the database.

Phoenix projects generate them for your models automatically, but for other Elixir projects, you can see an example here.

Summary

Callbacks

Fetches all entries from the Datastore for the Model

Deletes a struct using its primary key

Similar to delete/1 but returns the struct or raises if the changeset is invalid

Deletes all entries of the model

Fetches a single struct from the data store where the primary key matches the given id

Similar to get/1 but raises Ecto.NoResultsError if no record was found

Fetches a single struct from the data store that matches the passed clauses

Similar to get_by/1 but raises Ecto.NoResultsError if no record was found

Inserts a new record (Can be a struct, changeset, keyword list or a map)

Similar to insert/1 but returns the struct or raises if the changeset is invalid

Updates the database record using a modified struct or a changeset

Updates the database record using a Keyword list or a Map and a Struct for comparison

Similar to update/1 but returns the struct or raises if the changeset is invalid

Similar to update/2 but returns the struct or raises if the changeset is invalid

Callbacks

all()
all :: [Ecto.Schema.t] | no_return

Fetches all entries from the Datastore for the Model

See Ecto.Repo.all/2.

Example

Post.all
delete(struct_or_changeset)
delete(struct_or_changeset :: Ecto.Schema.t | Ecto.Changeset.t) ::
  {:ok, Ecto.Schema.t} |
  {:error, Ecto.Changeset.t}

Deletes a struct using its primary key.

Returns {:ok, struct} if the struct was successfully deleted or {:error, changeset} if there was a validation or a known constraint error.

See Ecto.Repo.delete/2.

Example

case Post.delete(post) do
  {:ok, struct}       -> # Deleted with success
  {:error, changeset} -> # Something went wrong
end
delete!(struct_or_changeset)
delete!(struct_or_changeset :: Ecto.Schema.t | Ecto.Changeset.t) ::
  Ecto.Schema.t |
  no_return

Similar to delete/1 but returns the struct or raises if the changeset is invalid.

Also see Ecto.Repo.delete!/2.

delete_all()
delete_all :: {integer, nil | [term]} | no_return

Deletes all entries of the model

Returns a tuple containing the number of items deleted. Also see Ecto.Repo.delete_all/2.

Example

Post.delete_all
# => {34, nil}
get(id)
get(id :: term) :: Ecto.Schema.t | nil | no_return

Fetches a single struct from the data store where the primary key matches the given id.

Returns nil if no result was found. If the struct in the queryable has no or more than one primary key, it will raise an argument error. See Ecto.Repo.get/3.

Example

Post.get(3)
Post.get("0e531047-6bd2-4ab1-94c3-817fba988dbe")
get!(id)
get!(id :: term) :: Ecto.Schema.t | nil | no_return

Similar to get/1 but raises Ecto.NoResultsError if no record was found.

Also see Ecto.Repo.get!/3.

get_by(clauses)
get_by(clauses :: Keyword.t) :: Ecto.Schema.t | nil | no_return

Fetches a single struct from the data store that matches the passed clauses.

Returns nil if no result was found. See Ecto.Repo.get_by/3.

Example

Post.get_by(title: "Introduction to Elixir")
Post.get_by(published_date: "2015-10-15")
get_by!(clauses)
get_by!(clauses :: Keyword.t) :: Ecto.Schema.t | nil | no_return

Similar to get_by/1 but raises Ecto.NoResultsError if no record was found.

Also see Ecto.Repo.get_by!/3.

insert(struct)
insert(struct :: Ecto.Schema.t | Ecto.Changeset.t | Map.t | Keyword.t) ::
  {:ok, Ecto.Schema.t} |
  {:error, Ecto.Changeset.t}

Inserts a new record (Can be a struct, changeset, keyword list or a map).

In case a changeset is given, the changes in the changeset are merges with the struct fields and all of them are sent to the database.

In case a struct, keyword list or a map is given, they are first converted to a changeset, with all non-nil fields as part of the changeset and inserted into the database if it’s valid.

Returns a {:ok, struct} if it was successfully inserted, or a {:error, changeset} is there was a validation or a known constraint error.

Also see Ecto.Repo.insert/2.

Requires a changeset method

This method depends on your model exporting a public changeset function. See this for more details.

Example

Post.insert(title: "Introduction to Elixir")
Post.insert(%{title: "Building your first Phoenix app"})
Post.insert(%Post{title: "Concurrency in Elixir", categories: ["programming", "elixir"]})

Post.changeset(%Post{}, %{title: "Ecto for dummies"}) |> Post.insert
insert!(struct)
insert!(struct :: Ecto.Schema.t | Ecto.Changeset.t | Map.t | Keyword.t) ::
  Ecto.Schema.t |
  no_return

Similar to insert/1 but returns the struct or raises if the changeset is invalid.

Also see Ecto.Repo.insert!/2.

update(modified_struct_or_changeset)
update(modified_struct_or_changeset :: Ecto.Schema.t | Ecto.Changeset.t) ::
  {:ok, Ecto.Schema.t} |
  {:error, Ecto.Changeset.t}

Updates the database record using a modified struct or a changeset.

This method only accepts one argument; either a modified struct or a changeset. It uses the struct or changeset’s primary key to update the correct record in the database. If no primary key is found, Ecto.NoPrimaryKeyFieldError will be raised.

Returns {:ok, struct} if the struct has been successfully updated or {:error, changeset} if there was a validation or a known constraint error.

Requires a changeset method

This method depends on your model exporting a public changeset function. See this for more details.

Example

post = Post.get_by!(id: 3)
post = %{ post | title: "Updated post title"}

Post.update(post)
update(struct, params)
update(struct :: Ecto.Schema.t, params :: Map.t | Keyword.t) ::
  {:ok, Ecto.Schema.t} |
  {:error, Ecto.Changeset.t}

Updates the database record using a Keyword list or a Map and a Struct for comparison.

This method accepts two arguments, the first being the struct that has to be updated, and the second being a Map or a Keyword List of the new values.

Returns {:ok, struct} if the struct has been successfully updated or {:error, changeset} if there was a validation or a known constraint error. Also see Ecto.Repo.update/2.

Requires a changeset method

This method depends on your model exporting a public changeset function. See this for more details.

Example

post = Post.get_by!(id: 3)
Post.update(post, title: "New post title", author_id: new_author_id)
update!(modified_struct_or_changeset)
update!(modified_struct_or_changeset :: Ecto.Schema.t | Ecto.Changeset.t) ::
  Ecto.Schema.t |
  no_return

Similar to update/1 but returns the struct or raises if the changeset is invalid.

update!(struct, params)
update!(struct :: Ecto.Schema.t, params :: Map.t | Keyword.t) ::
  Ecto.Schema.t |
  no_return

Similar to update/2 but returns the struct or raises if the changeset is invalid.