Unknown column 'mnum' in 'order clause'
select id,classid,ttid,onclick,plnum,totaldown,newspath,filename,userid,username,firsttitle,isgood,ispic,istop,isqf,ismember,isurl,truetime,lastdotime,havehtml,groupid,userfen,titlefont,titleurl,stb,fstb,restb,keyboard,title,titlepic,newstime,video,fg,xrq,price,ruanjian,downfen,filesize from ***_ecms_map where classid in (651,1684,1685,1686,1687,1688,1689,1690,1691,1692,1693,1694,1695,1696) and (filesize<='50') order by istop desc,mnum desc,downfen desc,totaldown desc limit 0,40