ecto-schema-patterns

# Ecto Schema Patterns

Master Ecto schemas to define robust data structures for your Elixir applications.
This skill covers schema definitions, field types, associations, embedded schemas,
and advanced patterns for modeling complex domain data.

## Basic Schema Definition

```elixir
defmodule MyApp.User do
  use Ecto.Schema

  schema "users" do
    field :name, :string
    field :email, :string
    field :age, :integer
    field :confirmed_at, :naive_datetime

    timestamps()
  end
end
```

Schemas map to database tables and define the structure of your data. Each schema
has a source name (table name) and a list of fields with their types. The `timestamps()`
macro automatically adds `inserted_at` and `updated_at` fields.

## Field Types and Options

```elixir
defmodule MyApp.Product do
  use Ecto.Schema

  schema "products" do
    # Standard field types
    field :title, :string
    field :description, :string
    field :price, :decimal
    field :quantity, :integer
    field :is_active, :boolean, default: true
    field :published_at, :utc_datetime

    # Enum type
    field :status, Ecto.Enum, values: [:draft, :published, :archived]

    # Map type for unstructured data
    field :metadata, :map

    # Array type
    field :tags, {:array, :string}

    # Binary type for binary data
    field :image_data, :binary

    # Virtual field (not persisted to database)
    field :display_price, :string, virtual: true

    timestamps()
  end
end
```

Ecto supports a wide range of field types including strings, integers, decimals,
booleans, datetime types, enums, maps, arrays, and binary data. Virtual fields
exist only in memory and are useful for computed values.

## Using Map Type for Flexible Data

```elixir
defmodule MyApp.User do
  use Ecto.Schema

  schema "users" do
    field :name, :string
    field :email, :string
    field :data, :map

    timestamps()
  end
end

# Usage
user = %MyApp.User{
  name: "John Doe",
  email: "john@example.com",
  data: %{
    preferenc