Re: updating unique columns

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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;


| UPDATE
| orderby SET orderby = orderby +10
| WHERE groupid IN
| ( SELECT groupid
|  FROM TABLE WHERE group_id = 1
|  ORDER BY orderby DESC )

No idea what you are trying to do here: try posting the actual SQL
used. However, an ORDER BY has no meaning inside of a subselect
passed to IN, as IN treats the list as bag of values, and does not
care about the internal order.

- --
Greg Sabino Mullane greg@turnstep.com
PGP Key: 0x14964AC8 200606011030
http://biglumber.com/x/web?pk=2529DF6AB8F79407E94445B4BC9B906714964AC8

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