Rails transactions within transactions?

Question

What happens when you have transactions with transactions

def a
  ActiveRecord::Base.transaction do
    # stuff
  end
end

ActiveRecord::Base.transaction do
  a
  # more stuff
end

What happens if the inner transaction succeeds but the outer fails and vice versa? What happens when both succeed or fail?

Answer 1

transaction calls can be nested. By default, this makes all database statements in the nested transaction block become part of the parent transaction.

The behaviour is well described in the documentation