Transactions for multiple models

I have users and companies tables where users belongs_to companies.

def signup
@company = Company.new(params[:company])
@user = User.new(params[:company])
@user.company = @company
if @user.valid? and @company.valid?
@company.save
@user.save
end
end

How can I make this into a transaction? Is this a candidate for a
distributed transaction?

If so, from what I understand from the API, I’d have to do:

Company.transaction do
@company.save
User.transaction do
@user.save
end
end

which is apparently unsafe. Or should I do this in SQL? Help!

I think I’ve got the answer:

def signup
@user = User.new(@params[:user])
@user.company = Company.new(@params[:company])
@user.address = Address.new(@params[:address])
if @request.post? and @user.valid?
User.transaction do
@user.save
#return
@user.company.addresses << @user.address
end
flash[:notice] = ‘Signup successful’
redirect_to :action => ‘welcome’, :user => @user
else
flash.now[:notice] = ‘Signup failed’
end
end

In the log:

BEGIN
INSERT INTO companies (name) VALUES (‘acme’)
INSERT INTO addresses (company_id, street) VALUES (NULL, ‘Smith
Street’)
INSERT INTO users (name, address_id, company_id) VALUES VALUES
(‘John’, 13, 8)
SELECT * FROM addresses WHERE addresses.company_id = 8
37mUPDATE addresses SET street = ‘Dunkerstr’, company_id = 8 WHERE
id = 13
COMMIT

Did a rudimentary test (uncommented ‘return’) and nothing was committed.