XF 1.3 Set user's registration date to their first post date

[Valter]

What would be mysql query to set user's registration-date to their first-post-date for usergroup X?

Many thanks.

 

[Jake Bunce]

UPDATE xf_user AS u
SET u.register_date = (
    SELECT p.post_date
    FROM xf_post AS p
    WHERE p.user_id = u.user_id
    ORDER BY p.post_date
    ASC
    LIMIT 0,1
)
WHERE u.user_group_id = 2

Backup first.

 

[Valter]

Thank You very much.