Use when defining and working with Ecto schemas including field types, associations, and embedded schemas. Use when modeling database entities in Elixir.
Master Ecto schema definitions to model your database entities effectively in Elixir applications.
defmodule MyApp.Accounts.User do
use Ecto.Schema
import Ecto.Changeset
schema "users" do
field :email, :string
field :name, :string
field :age, :integer
field :is_active, :boolean, default: true
field :role, Ecto.Enum, values: [:user, :admin, :moderator]
timestamps()
end
def changeset(user, attrs) do
user
|> cast(attrs, [:email, :name, :age, :is_active, :role])
|> validate_required([:email, :name])
|> validate_format(:email, ~r/@/)
|> validate_number(:age, greater_than: 0)
|> unique_constraint(:email)
end
end
schema "products" do
# Basic types
field :name, :string
field :price, :decimal
field :quantity, :integer
field :is_available, :boolean
field :rating, :float
# Date and time
field :released_on, :date
field :sale_starts_at, :naive_datetime
field :sale_ends_at, :utc_datetime
# Complex types
field :tags, {:array, :string}
field :metadata, :map
field :settings, {:map, :string} # map with string values
# Binary data
field :image_data, :binary
field :uuid, :binary_id
timestamps()
end
defmodule MyApp.Blog.Post do
use Ecto.Schema
schema "posts" do
field :title, :string
field :body, :string
# Belongs to
belongs_to :author, MyApp.Accounts.User
# Has many
has_many :comments, MyApp.Blog.Comment
# Has one
has_one :featured_image, MyApp.Blog.Image
# Many to many
many_to_many :tags, MyApp.Blog.Tag, join_through: "posts_tags"
timestamps()
end
end
defmodule MyApp.Blog.Comment do
use Ecto.Schema
schema "comments" do
field :content, :string
belongs_to :post, MyApp.Blog.Post
belongs_to :user, MyApp.Accounts.User
timestamps()
end
end
defmodule MyApp.Accounts.Address do
use Ecto.Schema
# Embedded schema - stored as JSON in parent
embedded_schema do
field :street, :string
field :city, :string
field :state, :string
field :zip, :string
field :country, :string, default: "US"
end
def changeset(address, attrs) do
address
|> cast(attrs, [:street, :city, :state, :zip, :country])
|> validate_required([:street, :city, :state, :zip])
end
end
defmodule MyApp.Accounts.User do
use Ecto.Schema
schema "users" do
field :name, :string
# Single embedded
embeds_one :billing_address, MyApp.Accounts.Address, on_replace: :update
# Multiple embedded
embeds_many :shipping_addresses, MyApp.Accounts.Address, on_replace: :delete
timestamps()
end
def changeset(user, attrs) do
user
|> cast(attrs, [:name])
|> cast_embed(:billing_address)
|> cast_embed(:shipping_addresses)
end
end
defmodule MyApp.Accounts.User do
use Ecto.Schema
schema "users" do
field :email, :string
field :password_hash, :string
# Virtual fields - not persisted
field :password, :string, virtual: true
field :password_confirmation, :string, virtual: true
field :full_name, :string, virtual: true
timestamps()
end
def changeset(user, attrs) do
user
|> cast(attrs, [:email, :password, :password_confirmation])
|> validate_required([:email, :password])
|> validate_confirmation(:password)
|> hash_password()
end
defp hash_password(changeset) do
case get_change(changeset, :password) do
nil -> changeset
password -> put_change(changeset, :password_hash, Bcrypt.hash_pwd_salt(password))
end
end
end
Use ecto-schemas when you need to: