Question

我一直在寻找一种解决方案，以获取只需要保留小数点后两位的学生百分比，所以我尝试了

select ROUND(count(fname) * 100.0/(select count(*) from stud_info  WHERE grade = 'FOUR'),2)as 'Total',
status as 'NutritionalStatus'
from stud_info
where grade = 'FOUR'
group by status

然后它最多打印出11个零位的小数位，您能帮我解决什么问题吗？我有ms sql 2014

Answer 1

首先，我建议您这样写：

select status,
       avg(case when grade = 'FOUR' then 1.0 else 0 end) as Total
from stud_info
where grade = 'FOUR'
group by status;

然后，如果要两位小数，请转换为小数：

select status,
       convert(decimal(6, 2),
               avg(case when grade = 'FOUR' then 1.0 else 0 end)
              ) as Total
from stud_info
where grade = 'FOUR'
group by status;

round()会更改值，但不会更改类型。应用程序/表示层仍可能决定显示不必要的零。

您还可以使用format()或str()将值转换为字符串。

SQL打印浮点数较大的小数位

1 个答案: