In SQL, how can you “group by” in ranges?

Question

Suppose I have a table with a numeric column (lets call it \"score\").

I\'d like to generate a table of counts, that shows how many times scores appeared in each ran

Answer 1

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;

Answer 2

Because the column being sorted on (Range) is a string, string/word sorting is used instead of numeric sorting.

As long as the strings have zeros to pad out the number lengths the sorting should still be semantically correct:

SELECT t.range AS ScoreRange,
       COUNT(*) AS NumberOfOccurrences
  FROM (SELECT CASE
                    WHEN score BETWEEN 0 AND 9 THEN '00-09'
                    WHEN score BETWEEN 10 AND 19 THEN '10-19'
                    ELSE '20-99'
               END AS Range
          FROM Scores) t
 GROUP BY t.Range

If the range is mixed, simply pad an extra zero:

SELECT t.range AS ScoreRange,
       COUNT(*) AS NumberOfOccurrences
  FROM (SELECT CASE
                    WHEN score BETWEEN 0 AND 9 THEN '000-009'
                    WHEN score BETWEEN 10 AND 19 THEN '010-019'
                    WHEN score BETWEEN 20 AND 99 THEN '020-099'
                    ELSE '100-999'
               END AS Range
          FROM Scores) t
 GROUP BY t.Range

Answer 3

select t.range as score, count(*) as Count 
from (
      select UserId,
         case when isnull(score ,0) >= 0 and isnull(score ,0)< 5 then '0-5'
                when isnull(score ,0) >= 5 and isnull(score ,0)< 10 then '5-10'
                when isnull(score ,0) >= 10 and isnull(score ,0)< 15 then '10-15'
                when isnull(score ,0) >= 15 and isnull(score ,0)< 20 then '15-20'               
         else ' 20+' end as range
         ,case when isnull(score ,0) >= 0 and isnull(score ,0)< 5 then 1
                when isnull(score ,0) >= 5 and isnull(score ,0)< 10 then 2
                when isnull(score ,0) >= 10 and isnull(score ,0)< 15 then 3
                when isnull(score ,0) >= 15 and isnull(score ,0)< 20 then 4             
         else 5  end as pd
     from score table
     ) t

group by t.range,pd order by pd

Answer 4

Neither of the highest voted answers are correct on SQL Server 2000. Perhaps they were using a different version.

Here are the correct versions of both of them on SQL Server 2000.

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'
    else '20-99' end as range
  from scores) t
group by t.range

or

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

Answer 5

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

Answer 6

I see answers here that won't work in SQL Server's syntax. I would use:

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

EDIT: see comments