set @username = "PBbot";

set @categoryname = "Miasta_w_Mołdawii";

​

select

    rev_timestamp,

    page_title,

    page_namespace,

    comment_text

from revision

    inner join actor on actor_id = rev_actor

    inner join comment on comment_id = rev_comment_id

    inner join page on page_id = rev_page

    inner join categorylinks on cl_from = page_id

where

    actor_name = @username and

    cl_to = @categoryname

order by

    rev_id desc;