也许你问的是如何让这样的事情继续下去……

当然，您将为查询调用全表扫描，如果包含需要统计(聚合)的分数的表很大，您可能想要一个性能更好的解决方案，您可以创建一个辅助表并使用规则，例如关于插入—您可能会研究它。

不过，并不是所有的RDBMS引擎都有规则!

Try

SELECT (str(range) + "-" + str(range + 9) ) AS [Score range], COUNT(score) AS [number of occurances]
FROM (SELECT  score,  int(score / 10 ) * 10  AS range  FROM scoredata )  
GROUP BY range;

另一种方法是将范围存储在表中，而不是将它们嵌入到查询中。你最终会得到一个表，命名为Ranges，它看起来像这样:

LowerLimit   UpperLimit   Range 
0              9          '0-9'
10            19          '10-19'
20            29          '20-29'
30            39          '30-39'

查询如下所示:

Select
   Range as [Score Range],
   Count(*) as [Number of Occurences]
from
   Ranges r inner join Scores s on s.Score between r.LowerLimit and r.UpperLimit
group by Range

这确实意味着要建立一个表，但是当所需的范围发生变化时，维护这个表是很容易的。不需要更改代码!

create table scores (
   user_id int,
   score int
)

select t.range as [score range], count(*) as [number of occurences]
from (
      select user_id,
         case when score >= 0 and score < 10 then '0-9'
         case when score >= 10 and score < 20 then '10-19'
         ...
         else '90-99' as range
     from scores) t
group by t.range

我会用一种稍微不同的方式来做，这样它就不必定义每种情况:

select t.range as [score range], count(*) as [number of occurences]
from (
  select FLOOR(score/10) as range
  from scores) t
group by t.range

没有测试过，但你懂的…

select cast(score/10 as varchar) + '-' + cast(score/10+9 as varchar), 
       count(*)
from scores
group by score/10