Thank you very much, i understand now :) Paul
On Tue, Apr 12, 2011 at 4:42 PM, Kevin Grittner <kevin.gritt...@wicourts.gov > wrote: > "Paul" <paul.co...@punct.ro> wrote: > > > update cart set status = 1 where userid = (select userid from > > users where email = 'exam...@example.com'); > > > > As you can see, the subquery is broken (users table doesn't have > > the column userid). > > By standard, if the identifier isn't defined within the most local > scope, each enclosing scope, from the inside out, will be checked. > I would expect the above to update each row where cart.userid was > not null. > > I always use and recommend aliases where practical. If you wrote it > this way, such a mistake would be clearly identified: > > update cart set status = 1 where userid = (select u.userid from > users u where u.email = 'exam...@example.com'); > > Not a bug. > > -Kevin >
