除以2的数字将返回0

我会用两个

sum

select sum       ( case         when endOfUse is null and addDate >= '1/1/2014'         then 1         else 0         end       )       * 100.0 -- if you want the usual 0..100 range for percentages       /       sum       ( case         when addDate >= '1/1/2014'         then 1         else 0         end       )       percentagefrom   saxref..AuthCycle