View Source Ecto Entity

Introduction

The missing Elixir Phoenix package to achieve Ecto > 80% common operations with < 20% effort.

Inspired by Laravel/ Php Eloquent package, Ecto Entity includes injectable functions that makes it enjoyable to interact with your database. When using Ecto Entity, each database table has a corresponding Schema(Model) that is used to interact with that table. In addition to retrieving records from the database table, Ecto Entity allows you to insert, update, and delete records from the table as well.

The goal of this package is to make it deadly simple to interact with Ecto without having to necessary write custom CRUD operations.

Getting Started

This guide is an introduction to Ecto Entity, the missing Phoenix Ecto package to achieve +80% of common operations less than 20% of effort it would normally take. Ecto Entity provides a standardized API and a set of abstractions for interacting with database tables, so that your phoenix Elixir developers can focus on what's specific to your project.

In this guide, we're going to learn some basics about Ecto Entity, such as creating, reading, updating and destroying records from a database. If you want to see the code from this guide, you can view it at kamaroly/ecto_entity on GitHub.

This guide will require you to have setup Entity beforehand.

Installation

To add Entity to your application, The first step is to add Entity to your mix.exs file, which we'll do by changing the deps definition in that file to this:


  defp deps do
    [
      {:ecto_entity, "~> 0.1.1"}
    ]
  end

Then, to install it, you will run this command:

mix deps.get

configure-your-ecto-repo

Configure Your Ecto Repo

Ecto Entity needs to know what repository to use while running database query. To do that, add config :ecto_entity, app_name: :your_app_name to your config/config.exs file. :your_app_name will be often the app configured in mix.exs under project > app.

import Config
 
# Configure your APP name so that Ecto Entity can know
# What Ecto Repo to use for the entity
config :ecto_entity, app_name: :your_ecto_elixir_app_name

adding-entity-to-your-schema

Adding Entity To Your Schema

To start off with, we'll need to include Entity in our existing Phoenix Schema using use Ecto.Entity in your Schema module, like the following:


  defmodule MyApp.Person do
    import Ecto.Changeset
    use Ecto.Schema
    use Ecto.Entity # Include Entity in your normal schema

    schema "people" do
      field :first_name, :string
      field :last_name, :string
      field :age, :integer
    end

    def changeset(entity, attrs) do
      entity
      |> cast(attrs, [:first_name, :last_name])
      |> validate_required([:first_name, :last_name])
    end
  end

NOTE: You must define a changeset/2 function to create and update your schema

CREATE

create/1 and insert/1 can be used to stores create table entry. Schema module must have changeset method implementedUse the create method, which accepts an schema of attributes, creates, and inserts it into the database.

The newly created schema will be returned by the create function.

iex> Person.create(%{first_name: "Hand", last_name: "Turner", age: 3})
{:ok,
%Person{
  __meta__: #Ecto.Schema.Metadata<:loaded, "people">,
  id: 125,
  first_name: "Hand",
  last_name: "Turner",
  age: 3
}}

Or you may create many entries at once by passing a list of entries to create_many/1.

Person.create_many([
  %{first_name: "Parisian", last_name: "Beier", age: 7},
  %{first_name: "Lang", last_name: "Emard", age: 3}
])

READ

find-1

find/1

Returns entry with id matching what passed

  iex(1)> Person.find(5)
  %Person{
    __meta__: #Ecto.Schema.Metadata<:loaded, "people">,
    id: 5,
    first_name: "Kristopher",
    last_name: "Keeling",
    age: 9
  }

or find multiple entities with the provided identifiers like the following

Person.find([1, 2, 3])

all-0

all/0

Returns all database entries from a schema module


iex> Person.all()
    [
      %Person{
        __meta__: #Ecto.Schema.Metadata<:loaded, "people">,
        id: 1,
        first_name: "German",
        last_name: "OConnell",
        age: 2
      },
      %Person{
        __meta__: #Ecto.Schema.Metadata<:loaded, "people">,
        id: 2,
        first_name: "Fritsch",
        last_name: "Kassulke",
        age: 8
      },
      %Person{
        __meta__: #Ecto.Schema.Metadata<:loaded, "people">,
        id: 3,
        first_name: "Russel",
        last_name: "Collins",
        age: 3
      }
    ]

take-1

take/1

or take a specific number of records

iex> Person.take(2)
  [
  %Person{
    __meta__: #Ecto.Schema.Metadata<:loaded, "people">,
    id: 1,
    first_name: "German",
    last_name: "OConnell",
    age: 2
  },
  %Person{
    __meta__: #Ecto.Schema.Metadata<:loaded, "people">,
    id: 2,
    first_name: "Fritsch",
    last_name: "Kassulke",
    age: 8
  }
]

first-0

first/0

Returns the first table entry


iex(1)> Person.first()
%Person{
  __meta__: #Ecto.Schema.Metadata<:loaded, "people">,
  id: 1,
  first_name: "Johnson",
  last_name: "Bradtke",
  age: 4
}
iex(2)>

last-0

last/0

Returns the last table entry


iex(1)> Person.last()

%Person{
  __meta__: #Ecto.Schema.Metadata<:loaded, "people">,
  id: 36,
  first_name: "Cedrick",
  last_name: "Donnelly",
  age: 2
}

except-1

except/1

Returns results except the records with the id provided

iex(1)> Person.all()
[
  %Person{
    __meta__: #Ecto.Schema.Metadata<:loaded, "people">,
    id: 1,
    first_name: "Hudson",
    last_name: "Berge",
    age: 9
  },
  %Person{
    __meta__: #Ecto.Schema.Metadata<:loaded, "people">,
    id: 2,
    first_name: "Hamill",
    last_name: "Wunsch",
    age: 2
  },
  %Person{
    __meta__: #Ecto.Schema.Metadata<:loaded, "people">,
    id: 3,
    first_name: "Alden",
    last_name: "Kovacek",
    age: 0
  }
]
iex(2)> Person.except([1, 2])
[
  %Person{
    __meta__: #Ecto.Schema.Metadata<:loaded, "people">,
    id: 3,
    first_name: "Alden",
    last_name: "Kovacek",
    age: 0
  }
]

Or provide only 1 record to exclude

iex(1)> Person.except(1)
[
  %Person{
    __meta__: #Ecto.Schema.Metadata<:loaded, "people">,
    id: 2,
    first_name: "Hamill",
    last_name: "Wunsch",
    age: 2
  },
  %Person{
    __meta__: #Ecto.Schema.Metadata<:loaded, "people">,
    id: 3,
    first_name: "Alden",
    last_name: "Kovacek",
    age: 0
  }
]

UPDATE

Updates an existing entry

update-2

update/2

Updates an existing record identified by an ID

  iex> Person.update(1, %{first_name: "Kamaro"})
  iex> {:ok,
        %Person{
          __meta__: #Ecto.Schema.Metadata<:loaded, "people">,
          id: 1,
          first_name: "Kamaro",
          last_name: "Yundt",
          age: 7
        }}

updates-2

updates/2

Updates an existing record identified by its Schema(Model)


iex(1)> person = Person.find(1)
%Person{
  __meta__: #Ecto.Schema.Metadata<:loaded, "people">,
  id: 1,
  first_name: "Weber",
  last_name: "Ok 2",
  age: 7
}
iex(2)> Person.update(person, %{first_name: "Kamaro"})
  {:ok,
  %Person{
    __meta__: #Ecto.Schema.Metadata<:loaded, "people">,
    id: 1,
    first_name: "Kamaro",
    last_name: "Ok 2",
    age: 7
  }}

You may update many entries at once using update_many/2 like the following

iex> query = Person.not_in_ids(1)
iex> Person.update_many(query, [first_name: "Kamaro Paul"])
    {:ok, %{update_all: {2, nil}}}

DELETE

delete/1

You may use delete/1 or destroy/1 to delete an existing table entry identifies by its ID.

iex(2)> Person.delete(7)
    {:ok,
    %Person{
      __meta__: #Ecto.Schema.Metadata<:deleted, "people">,
      id: 7,
      first_name: "Glover",
      last_name: "Schimmel",
      age: 2
    }}

delete/1 works the same as destroy/1. It's just a preference in pronunciation.


iex(3)> Person.destroy(2)
{:ok,
%Person{
  __meta__: #Ecto.Schema.Metadata<:deleted, "people">,
  id: 2,
  first_name: "Ruecker",
  last_name: "Lemke",
  age: 0
}}

You may want to delete many records at once. You can do so by passing a list of the ids like the following. When you pass a list of ids to delete or destroy, Ecto.entity return {count_of_deleted_entities, nil}

iex(2)> Person.delete([3, 6])
{2, nil}

delete_except-1

delete_except/1

You may wish to delete entries with exception using delete_except/ or destroy_except/

iex(1)> Person.delete_except([47, 48])
{48, nil}
iex(2)> Person.all()
[
  %Person{
    __meta__: #Ecto.Schema.Metadata<:loaded, "people">,
    id: 47,
    first_name: "Toy",
    last_name: "Weimann",
    age: 3
  },
  %Person{
    __meta__: #Ecto.Schema.Metadata<:loaded, "people">,
    id: 48,
    first_name: "Wilderman",
    last_name: "Treutel",
    age: 9
  }
]

truncate

truncate

You may truncate a database table by truncate/0. truncate delete all entries and reset the table index.

iex(1)> Person.truncate()
{:ok,
 %MyXQL.Result{
   columns: nil,
   connection_id: 788,
   last_insert_id: 0,
   num_rows: 0,
   rows: nil,
   num_warnings: 0
 }}

CONDITIONS

Conditions help you to retrieve data based on the table fields. You may do it using where condition.

iex(1)> Person.where(:first_name, "Kamaro")
#Ecto.Query<from p0 in Person, where: p0.first_name == ^"Kamaro">

You may return the first entry that matches the provided where condition like the following:

iex(1)> Person.where_first(:first_name, "Dominic")
%Person{
  __meta__: #Ecto.Schema.Metadata<:loaded, "people">,
  id: 42,
  first_name: "Dominic",
  last_name: "Cummings",
  age: 6
}

Or return all entries that matches a given condition like the following:

iex(8)> Person.where_all(:age, 6)                                                                 
[                                                                                                      
  %Person{                                                                                             
    __meta__: #Ecto.Schema.Metadata<:loaded, "people">,                                                
    id: 9,                                                                                             
    first_name: "Kihn",                                                                                
    last_name: "Graham",                                                                               
    age: 6                                                                                             
  },                                                                                                   
  %Person{                                                                                             
    __meta__: #Ecto.Schema.Metadata<:loaded, "people">,                                                
    id: 15,                                                                                            
    first_name: "Cummerata",                                                                           
    last_name: "Altenwerth",                                                                           
    age: 6                                                                                             
  },                                                                                                   
  %Person{                                                                                             
    __meta__: #Ecto.Schema.Metadata<:loaded, "people">,                                                
    id: 37,                                                                                            
    first_name: "Pollich",                                                                             
    last_name: "Crist",                                                                                
    age: 6                                                                                             
  },                                                                                                   
  %Person{                                                                                             
    __meta__: #Ecto.Schema.Metadata<:loaded, "people">,                                                
    id: 39,                                                                                            
    first_name: "Daugherty",                                                                           
    last_name: "Mills",                                                                                
    age: 6                                                                                             
  },                                                                                                   
  %Person{                                                                                             
    __meta__: #Ecto.Schema.Metadata<:loaded, "people">,                                                
    id: 41,                                                                                            
    first_name: "Alfonso",                                                                             
    last_name: "Nitzsche",                                                                             
    age: 6                                                                                             
  },                                                                                                   
  %Person{                                                                                             
    __meta__: #Ecto.Schema.Metadata<:loaded, "people">,                                                
    id: 42,                                                                                            
    first_name: "Dominic",                                                                             
    last_name: "Cummings",                                                                             
    age: 6                                                                                             
  }                                                                                                    
]