ecto-multi

Ecto Transactions (Repo.transact)

Use Repo.transact for atomic multi-step database operations. Valified has moved away from Ecto.Multi/Valified.Sequence in favor of the cleaner Repo.transact API.

⚠️ PROJECT CONVENTION: Use Repo.transact

IMPORTANT: In Valified, use Repo.transact for multi-step transactions instead of Ecto.Multi or Valified.Sequence.

Benefits of Repo.transact:

• Simpler API: Just a function, no complex builders
• Standard Elixir: Works naturally with with/1
• Clearer control flow: Read top-to-bottom like normal code
• Automatic rollback: On exceptions or {:error, _} returns

Why Use Transactions?

Multi-step operations that must all succeed or all fail:

• Creating a user with account and permissions
• Processing a payment with multiple updates
• Complex workflows with multiple database operations
• Operations that need consistency guarantees

Benefits:

• Atomic: All operations succeed or all rollback
• Simple: Just wrap operations in Repo.transact
• Safe: No partial states in the database
• Familiar: Standard Elixir patterns

Basic Transaction Pattern

def create_user_with_account(user_attrs, account_attrs) do
  Repo.transact(fn ->
    with {:ok, user} <- Repo.insert(User.changeset(%User{}, user_attrs)),
         {:ok, account} <- Repo.insert(Account.changeset(%Account{user_id: user.id}, account_attrs)) do
      {:ok, %{user: user, account: account}}
    end
  end)
end

Returns:

• {:ok, %{user: user, account: account}} if all operations succeed
• {:error, changeset} if any operation fails
• Transaction automatically rolls back on error

Transaction Patterns

1. Simple Transaction (Arity 0)

Just wrap operations, uses default Repo:

def create_company_with_admin(company_attrs, admin_attrs) do
  Repo.transact(fn ->
    with {:ok, company} <- Repo.insert(Company.changeset(%Company{}, company_attrs)),
         {:ok, admin} <- Repo.insert(User.changeset(%User{company_id: company.id}, admin_attrs)) do
      {:ok, company}
    end
  end)
end