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

我在这里看到的答案在SQL Server的语法中行不通。我会用:

select t.range as [score range], count(*) as [number of occurences]
from (
  select case 
    when score between  0 and  9 then ' 0-9 '
    when score between 10 and 19 then '10-19'
    when score between 20 and 29 then '20-29'
    ...
    else '90-99' end as range
  from scores) t
group by t.range

编辑:见评论

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!

在我看来，James Curran的回答是最简洁的，但输出并不正确。对于SQL Server，最简单的语句如下:

SELECT 
    [score range] = CAST((Score/10)*10 AS VARCHAR) + ' - ' + CAST((Score/10)*10+9 AS VARCHAR), 
    [number of occurrences] = COUNT(*)
FROM #Scores
GROUP BY Score/10
ORDER BY Score/10

这假设了一个我用来测试它的#Scores临时表，我只是用0到99之间的随机数填充了100行。

select t.blah as [score range], count(*) as [number of occurences]
from (
  select case 
    when score between  0 and  9 then ' 0-9 '
    when score between 10 and 19 then '10-19'
    when score between 20 and 29 then '20-29'
    ...
    else '90-99' end as blah
  from scores) t
group by t.blah

如果在MySQL中，请确保使用'range'以外的单词，否则在运行上述示例时会出现错误。

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!