complex update statement

[Chris Reimann]

I want to update this table based on a rather complex logic in terms of what UPDATE can handle - as far as I know...

The table ("example") design:

id         MEDIUMINT UNSIGNED
user_id    MEDIUMINT UNSIGNED
isarchived TINYINT   UNSIGNED
more_data_cols...

1) i set them ALL to isarchived = 1

2) per DISTINCT user_id, i want ONLY 1 row to be isarchived = 0.
how do I go about doing that?

Thanks so much!