select 
         t.*,
         case 
            when p.description <> '' and p.post is not null then concat('<div class="IPBDescription">', p.description, '</div>', p.post)
            when p.description <> '' then p.description
            else p.post
         end as post,
         case when t.state = 'closed' then 1 else 0 end as closed,
         'IPB' as Format,
         p.ip_address,
         p.edit_time
      , from_unixtime(start_date) as start_date_Date, from_unixtime(edit_time) as edit_time_Date
from topics t
      left join posts p
         on t.topic_firstpost = p.pid
      where t.tid between -2000000000 and 2000000000;Unknown column 'p.description' in 'field list'
Error: (1024) Unknown column 'p.description' in 'field list'