On Mon, Feb 28, 2011 at 05:39:07PM -0500, Alan Acosta wrote:
> But i have a new problem there, i have no rows for update, i create new rows
> when the seats are sold, cause rarely the database knows the capacity of the
> bus, number of seats, even some bus doesn't have seat number 4 for example
> :p. So i cannot SELECT FOR UPDATE no existent rows, but i still need to lock
> in some way in order to check if seat number X was already sold or is free !
Someone else suggests that you need a uniqueness constraint, and I
agree. But I also don't understand how you can be ensuring not to
double-sell something if you don't have the list of inventory prior to
its being sold.
A
--
Andrew Sullivan
ajs@crankycanuck.ca