post_title like '%' || #{keyword}||'%'   post_content like '%' || #{keyword}||'%'   post_writer like '%' || #{keyword}||'%'        select * from (select rownum rno,b.* from board_post b where isshow != 'N'  order by post_no desc ) where rno between (#{pageNum}-1)*#{amount}+1 and (#{pageNum})*#{amount}