> Uhm, please ignore this email, it looks like this can't be done using
> transactions
>
> begin transaction;
> update book set "order"=2 where id=1;
> update book set "order"=1 where id=2;
> commit;
for atomic swapping, however, it can be done in a single obscure
SQL statement:
update book set order = 3 - order
where id=1 or id=2
Which follows the pattern
UPDATE tbl
SET field = (
SELECT SUM(field)
FROM tbl
WHERE [EMAIL PROTECTED] or [EMAIL PROTECTED]
) - field
WHERE [EMAIL PROTECTED] or [EMAIL PROTECTED]
Any help?
-tkc (aka "the atomic swapper"? :)
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