update attachment set business_type=#{business_type},business_id=#{business_id},del_flag=0
where id=#{id}
update attachment set del_flag=1
where business_type=#{business_type} and business_id=#{business_id}
update attachment set del_flag=1
where business_type=#{business_type} and business_id=#{business_id}
and id=#{id}