# `AshPostgres.Migration`
[🔗](https://github.com/ash-project/ash_postgres/blob/v2.9.0/lib/migration.ex#L5)

Utilities for use in migrations

# `create_enum`

A utility for creating postgres enums for an Ash enum type.

In your migration, you can say:

```elixir
def up() do
  AshPostgres.Migration.create_enum(MyEnumType)
end
```

Attribution:

This code and example was copied from ecto_enum. I didn't use the library itself
because it has a lot that would not currently be relevant for Ash.
https://github.com/gjaldon/ecto_enum

Must be done manually, as the migration generator will not do it.
Additionally, altering the type must be done in its own, separate migration, which
must have `@disable_ddl_transaction true`, as you cannot do this operation
in a transaction.

For example:

```elixir
defmodule MyApp.Repo.Migrations.AddToGenderEnum do
  use Ecto.Migration
  @disable_ddl_transaction true

  def up do
    Ecto.Migration.execute "ALTER TYPE gender ADD VALUE IF NOT EXISTS 'other'"
  end

  def down do
    ...
  end
end
```

Keep in mind, that if you want to create a custom enum type, you will want to add
```elixir
def storage_type(_), do: :my_type_name
```

# `drop_enum`

---

*Consult [api-reference.md](api-reference.md) for complete listing*