SQL：如何根据SQL另一列中的值范围求和一列？

Question

以下是我可用的数据：

rate     Fee
 0.12    48,599 
 0.29    80,718 
 0.37    94,110 
 0.44    75,289 
 0.62    79,236 
 0.85    99,210 

现在，我需要按以下方式进行总结：

Rate_classification               Fee
Low Rate (0 -to- 0.25)            48,599 
Moderate rate (0.25 -to- 0.75)    329,353 
High rate (0.75 -to- 1.00)        99,210 

谢谢。

Answer 1

在派生表中使用case表达式对费率进行分类。 GROUP BY结果GROUP BY ：

select rate_class, sum(fee)
from
(
    select case when rate < 0.25 then 'low rate'
                when rate < 0.75 then 'medium rate'
                else 'high rate'
           end as rate_class,
           Fee
    from tablename
) dt
group by rate_class

Answer 2

你可以尝试下面的方式

      select case when rate>=0 and rate<.25 then 'Low_Rate'
        case when rate>=.25 and rate<.75 then 'Moderate'
         else 'High' end as Rate_classification,
         sum(fee)           
    from your_table group by Rate_classification

Answer 3

这是一个替代解决方案，其中包括针对该问题的cte结构，同时尊重jarlh的回答。

;with cte (Rateclass,rate,fee) as (

   select Rateclass = (case when rate >=0.0 and rate < 0.25 then LowRate
                            when rate >=0.25 and rate < 0.75 then ModerateRate
                            when rate >=0.75 and rate < 1.0 then HighRate end),
          rate,
          fee
   from table

)
select Rateclass, sum(fee)
from cte
group by Rateclass