为什么我不能在用％符号进行连续后订购

Question

Select category, 
       concat(count(category) * 100/ (select count(*) from table3),'%') as category_percentage_males 
from   table3 
where  gender in ('m') 
group by category 
order by category_percentage_males desc

由于某种原因，一旦我结束，订单不会返回desc。没有concat订单工作正常。为什么会发生这种情况的任何原因？

Answer 1

这是您的查询：

Select category, concat(count(category) * 100/ (select count(*) from table3),'%') as category_percentage_males
from table3 where gender in ('m')
group by category
order by category_percentage_males desc;

我强烈建议您将其作为：

Select category,
       concat(avg(case when gender = 'm' then 100.0 else 0 end), '%') as category_percentage_males
group by category
order by avg(case when gender = 'm' then 100.0 else 0 end) desc;