select a.peijlb_dm,a.peijlb_mc
,peij_jcsl=sum(c.peij_jcsl)
,proportion=case 
when ((select sum_all=sum(peij_jcje) from kucshp_mx))=0 
or sum(c.peij_jcsl)=0
then '0%'
else cast(cast(
sum(c.peij_jcsl)*500.0
/(select sum_all=sum(peij_jcje) from kucshp_mx)
as decimal(10,2)) as varchar)+'%' end
from sm_peijlb a
left join kucshp_info b on a.peijlb_dm=b.peijlb_dm
left join kucshp_mx c on b.peij_no=c.peij_no
,(select sum_all=sum(peij_jcje) from kucshp_mx) d
group by a.peijlb_dm,a.peijlb_mc