sql case whenの使用及び別名問題

select 
htlb,
sum(HTZJE) as ysje,--    
sum(yfje) as ljfse,--     
sum(jyje) as jyje,--    
(sum(jyje) / sum(HTZJE)) as jezb, --    
(sum(yfje) / sum(HTZJE)) as fyzb,--    
case htlb
when '1' then 'cblb1'
when '2' then 'cblb2'
when '3' then 'cblb3'
ELSE '  ' END bieMing
from tb_table
group by htlb