Hi all. Maybe somebody can explain that to me:
def create
@orders = Order.find(:all, :conditions => [“products.member_id = ?”,
current_login.member.id])
new payment
@payment = Payment.new
@payment.member = current_login.member
@payment.status = Payment::STATUS_NEW
@payment.save
sum = 0.00
@orders.each do |order|
order.payment = @payment
order.save
sum += 2950
end
logger.info “COUNT A: #{@payment.orders_count}”
@payment.update_attribute(:total, sum)
@payment.reload
logger.info “COUNT B: #{@payment.orders_count}”
works fine but for one point:
The counter cache is 0 after that.
Reason is this.
While the line
order.payment = @payment
generates the necessary code to update the counter_cache (twice):
UPDATE payments SET orders_count = orders_count + 1 WHERE (id =
1017343603)
the update_attribute line updates more than necessary:
UPDATE payments SET created_at = ‘2008-06-03 18:42:03’, member_id
= 762526581, status = 1, orders_count = 0, total = 5900.0,
updated_at = ‘2008-06-03 18:42:03’ WHERE id = 1017343603
Why is it updating not only the total and updated_at, but in addition a
whole set of different columns, that where not even changed since the
@payment.save?
Am I doing something terribly wrong?
I could handle this for the specific problem, but I see a lot of
possible side effects here and would at least want to understand, what’s
the reason for Rails to behave that way…