sql - 在数据资源管理器中获取非整数结果

Question

Stack Exchange 数据资源管理器允许对 Stack Exchange 数据库进行 SQL 查询。以下查询——</p>

select
  month(CreationDate) month,
  year(CreationDate) year,
  sum(case when lower(left(Title,2))='wh' then 1 else 0 end)/count(*) wh,
  (select sum(Score)/count(*)
   from Posts u
   where
     month(CreationDate)=month(t.CreationDate) and
     year(CreationDate)=year(t.CreationDate) and
     lower(left(Title,2))='wh' and
     PostTypeId=1 -- question
  ) wh_score,
  sum(Score)/count(*) score,
  (select sum(AnswerCount)/count(*)
   from Posts u
   where
     month(CreationDate)=month(t.CreationDate) and
     year(CreationDate)=year(t.CreationDate) and
     lower(left(Title,2))='wh' and
     PostTypeId=1 -- question
  ) wh_answers,
  sum(AnswerCount)/count(*) answers
from Posts t
where PostTypeId=1 -- question
group by month(CreationDate), year(CreationDate)
;

—由Scorpi0提供 — 在结果中产生所有整数值：所有内容都被舍入或截断（我不知道是哪个）。（这在列中特别烦人，wh因此每个值都是0.）有没有办法强制小数或值？

Answer 1

像很多语言一样，当你做 1/2 时，它执行 1 除以 2 并返回商，所以这里是 0。

n/m => n = m * q + r
1/2 => 1 = 2 * 0 + 1

让我们务实一点：只需乘以小数，如下所示：

(sum(AnswerCount) * 1.0)/count(*)

你会得到十进制而不是整数。