""Greg Sabino Mullane"" <greg@turnstep.com>
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> | UPDATE
> | orderby SET orderby = orderby +10
> | WHERE groupid = 1;
> | -> FAILS because of UNIQUE INDEX
>
> One workaround is to do it in two steps, assuming that
> orderby is > 0 for all rows you are changing:
>
> BEGIN;
> UPDATE mytable SET orderby = -orderby WHERE groupid = 1;
> UPDATE mytable SET orderby = -orderby+10 WHERE groupid = 1;
> COMMIT;
Should we invent something to defer the check of uniqueness
to the end of the SQL command?
Regards,
William ZHANG