關於下列語法，為何不能以 'Total Salary' 進行排序?是有顯示，但是無法真的有排序
select ename, salary,hiredate,
case
when year(hiredate)<1980 then salary*2.5
when year(hiredate)>=1980 and year(hiredate)<1985 then salary*2.0
else salary*1.5
end 'Total Salary'
from cmdev.emp
order by 'Total Salary' asc |
